Anti-settling and thickening compositions and methods for using same

ABSTRACT

An anti-settling additive, composition containing the anti-settling additive, and methods for use in coating compositions or formulations. A HASE thickener with improved resistance to surfactants and anti-sag properties, compositions containing the thickener and methods for use of the thickener in coating compositions or formulations and the like. The anti-settling additive and the thickener being a polymer synthesized using a specialized associative monomer that contains C1-C4 alkyl, propylene oxide, ethylene oxide and a polymerizable group.

CROSS-REFERENCE TO RELATED APPLICATIONS

This claims the benefit of US provisional patent application no.61740999 filed Dec. 21, 2012, incorporated herein by reference in itsentirety.

FIELD OF THE INVENTION

The present invention relates to polymers for use as anti-settlingadditives for use in coating compositions/formulations and polymers foruse as HASE thickener with improved resistance to surfactants andanti-sag properties. These polymers are synthesized using a specializedassociative monomer that contains methyl, propylene oxide, ethyleneoxide and a polymerizable group. Preferably the polymers of the presentinvention have minimal viscosity reduction in the presence ofsurfactants.

BACKGROUND OF THE INVENTION

Anti-settling agents are used in the coatings industry to preventpigments or other finely divided solid particles from settling duringstorage. Anti-settling agents can be categorized as organic clay,polyamide, ethylene vinyl acetate polymers, fumed silica and calciumsulfonate derivatives. Many of these anti-settling agents, however, havetheir drawbacks. For example, organic clay and fumed silica cannegatively impact the coatings in which they are applied through glossdecrease and increase of viscosity of the paint, significantly affectingflow and leveling of the paint.

Anti-settling agents in a coating formulation requires additives whichgenerally maintain the proper viscosity of the coating formulation. Thisis sometimes difficult, as, for example, better control pigmentdispersion or settling means generally higher viscosities. Coatingcompositions with extremely high viscosities just after application maynegatively affect flow rates where, as a consequence, low flow ratesoccur and hinder the formation of a smooth film.

Conventional natural and synthetic polymers have limitations withrespect to use as thickeners in aqueous systems, particularly in paintsand coating compositions. In general, they do not provide a rheologicalprofile suitable for the desired flow and other properties required inpaints and coatings. For example, HEC swells rapidly in water and formslumps, which are not readily dispersible. A correct balance ofproperties must be achieved among the various additives.

Thickeners are used in paint to achieve particular rheologicalproperties such as the shear-rate-dependent behavior, to control theviscosity at low, medium and high shear rates, sag resistance andapplication viscosity. A type of associative thickener commonly found inlatex paints is known as hydrophobically-modified alkali-swellableemulsion (HASE) polymer. These HASE polymers are carboxyl functionalpolymers synthesized by free radical polymerization. HASE polymersystems can be prepared from the following monomers: (a) anethylenically unsaturated carboxylic acid, (b) a nonionic ethylenicallyunsaturated monomer, and (c) an ethylenically unsaturated hydrophobicmonomer.

HASE thickeners are based on a polyelectrolyte backbone, usuallymethacrylic acid and ethylacrylate copolymer, with pendant hydrophobes(i.e., hydrophobes attached to the backbone with polyethylene oxidechains). When neutralized with a suitable base, carboxylic acid groupsalong the polymer backbone are ionized to yield water-soluble polymers.The dissolution of particles results in changes in polymer conformationand solution rheology. A number of factors contribute to the thickeningeffect of HASE polymers: association of hydrophobic groups, topologicalentanglements, and chain expansion of high molecular weightpolyelectrolyte backbone.

Representative HASE copolymer systems include those shown in EP 226097B1, EP 705852 B1, U.S. Pat. No. 4,384,096, U.S. Pat. No. 5,874,495, U.S.Pat. No. 7,217,752 B2, and US Patent Application Publication2006/0270563 A1, now U.S. Pat. Nos. 7,772,421 and 8,071,674, and USPatent Application Publication 2012/0123149 to Yang et al, allincorporated herein by reference.

Three categories of polymers produced by emulsion polymerization are:(1) Synthetic rubber: some grades of styrene-butadiene (SBR), somegrades of polybutadiene, polychloroprene (Neoprene), nitrile rubber,acrylic rubber, fluoroelastomer (FKM); (2) Plastic: some grades of PVC,some grades of polystyrene, some grades of PMMA(polymethylmethacrylate), acrylonitrile-butadiene-styrene terpolymer(ABS), polyvinylidene fluoride, polytetrafluoroethylene (PTFE); and (3)Dispersions (i.e., polymers sold as aqueous dispersions).

Latex is an example of an emulsion polymer which is a water basedpolymer dispersion. Latex paints are used for a variety of applicationsincluding interior and exterior, and flat, semi-gloss and glossapplications. Latex is a stable dispersion (colloidal emulsion) ofrubber or plastic polymer microparticles in an aqueous medium. Latexesmay be natural or synthetic.

In spite of their many important advantages, HASE thickeners areinherently more sensitive to variations in coating composition. HASEthickeners interact with surfactants present in paint formulations andsuch interaction result in a large viscosity loss. Due to theinteraction with surfactants they require more attention in formulating.Paints thickened with HASE rheology modifiers are also more sensitive tothe addition of tinting colorants which contain surfactants and/ordispersants which can result in large viscosity drops. Often, aconsequence of this viscosity loss is inferior application propertiessuch as poor films build, sagging and severe color float.

As tinted and colored paints become more popular, the need for rheologymodifiers that can withstand the addition of colorants withoutsignificant viscosity loss has gained in importance.

Hydraulic fracturing of the subterranean formation is conducted toincrease oil and/or gas production. Fracturing is caused by injecting aviscous fracturing fluid or a foam at a high pressure (hereinafterinjection pressure) into the well to form a fracture. As the fracture isformed, the particulate material, referred to as a “propping agent” or“proppant” is placed in the formation to maintain the fracture in apropped condition when the injection pressure is released. Coated and/oruncoated particles are often used as proppants to keep open fracturesimposed by hydraulic fracturing upon a subterranean formation, e.g., anoil or gas bearing strata. Particles typically used to prop fracturesgenerally comprise sand or sintered ceramic particles as the fractureforms, the proppants are carried into the fracture by suspending them inadditional fluid or foam to fill the fracture with slurry of proppant inthe fluid or foam. Upon release of the pressure, the proppants form apack that serves to hold open the fractures. Thus, the proppantsincrease production of oil and/or gas by providing a conductive channelin the formation. There is a need for a proppant carrier that canprevent settling of proppants or sand being positioned in the fractures.

During primary recovery a subterranean formation produces the oil bypressure depletion. In pressure depletion, the pressure differencebetween the formation and a production well or wells forces the oilcontained within the formation toward a production well where it can berecovered. Typically, up to 35 percent of the oil initially contained ina formation can be recovered using pressure depletion. Methods have beendeveloped to recover oil which could not be recovered using onlypressure depletion techniques or secondary recovery techniques. Thesemethods are typically referred to as “enhanced oil recovery techniques”(EOR).

One enhanced oil recovery process is referred to as surfactant flooding.This generally covers the use of an aqueous fluid containing surfactantinjected into an oil rich formation to displace oil from the formationand the displaced oil is then recovered.

Another enhanced oil recovery process is referred to as chemicalflooding. This generally covers the use of polymer and/or surfactantslugs. In polymer flooding, a polymer solution is injected to displaceoil toward producing wells. The polymer solution is designed to developa favorable mobility ratio between the injected polymer solution and theoil/water bank being displaced ahead of the polymer. In surfactantflooding, an aqueous solution containing surfactant is injected into theoil rich formation. Residual oil drops are deformed as a result of lowinterfacial tension provided by surfactant solution and drops aredisplaced through the pore throats and displaced oil is then recovered.

U.S. Pat. No. 4,432,881, incorporated herein by reference in itsentirety, discloses an aqueous liquid medium having increased low shearviscosity as provided by dispersing into the aqueous medium (1) awater-soluble polymer having pendant hydrophobic groups, e.g., anacrylamide dodecyl acrylate copolymer, and (2) a water-dispersiblesurfactant, e.g., sodium oleate, or dodecyl polyethyleneoxy glycolmonoether.

U.S. Pat. No. 4,541,935, incorporated herein by reference in itsentirety, discloses fracturing processes which use aqueous hydraulicfracturing fluids. The fluids comprise: (a) an aqueous medium, and (b) athickening amount of a thickener composition comprising (i) awater-soluble or water-dispersible interpolymer having pendanthydrophobic groups chemically bonded thereto, (ii) a nonionic surfactanthaving a hydrophobic group(s) capable of associating with thehydrophobic groups on said organic polymer, and (iii) a water-solubleelectrolyte.

U.S. Pat. No. 5,566,760, incorporated herein by reference in itsentirety, discloses a fracturing fluid comprising surfactants andhydrophobically-modified polymers.

U.S. Pat. No. 7,084,095, incorporated herein by reference in itsentirety, discloses addition of polymers to a viscoelastic surfactantbase system allows adjusting the rheological properties of the basefluid.

U.S. Pat. No. 7,427,583, incorporated herein by reference in itsentirety, describes an aqueous viscoelastic fracturing fluid for use inthe recovery of hydrocarbons. The fluid comprises a viscoelasticsurfactant and a hydrophobically modified polymer.

U.S. Pat. No. 7,727,937 to Pauls et al, incorporated herein by referencein its entirety, discloses acidic treatment fluids used in industrialand/or subterranean operations, and more particularly, acidic treatmentfluids comprising clarified xanthan gelling agents, and methods of usein industrial and/or subterranean operations.

U.S. Pat. No. 7,772,421 to Yang et al, incorporated herein by referencein its entirety, discloses a hydraulic fracturing composition comprisingwater, a pH responsive polymer and a proppant.

U.S. Pat. No. 7,789,160 to Hough et al, incorporated herein by referencein its entirety discloses an aqueous fluid useful for the recovery ofcrude oil from a subterranean formation, which includes a compositionincluding a mixture of water, a water soluble block copolymer, aninorganic salt and at least one member of the group of a nonionicsurfactant having an HLB of less than 12, and methods for using same.

U.S. Pat. No. 7,857,055 to Li et al, incorporated herein by reference inits entirety, discloses a fluid for treating a subterranean formationcomprising an aqueous solution of a polysaccharide, a polyacrylamide, acrosslinking agent, and less than 0.1% by weight of any clay component,wherein the polyacrylamide is present in an amount of from about 0.01percent to about 1 percent by weight of the fluid.

It would be desirable to provide stable fracturing fluids and EOR fluidsfor subterranean formations, such as natural gas and/or oil field.

Also, there is a need to enhance viscosity to improve personal carecompositions. In personal care applications, consumers are increasinglydemanding formulations that provide multiple benefits such as, but notlimited to, unique sensory experience, enhanced moisturization,increased conditioning, improved delivery of active ingredients andcompatibility. Synthetic rheology modifier polymers can be employed toassist in achieving one or more of these properties.

Also there is a need to enhance viscosity to improve cleaningcompositions for home and industry.

SUMMARY OF THE INVENTION

Described herein are additives which control suspension of pigment, aswell as other fine solids, in coating and aqueous compositions. It hasbeen surprisingly discovered the additives, when used in lower molecularweights, for example 1,000 to 750,000 g/mol, as described herein provideant-settling stability while adding no or little viscosity to theaqueous system or coating. It is desirable in many cases for suchadditives not to impart additional viscosity or to impart very littleviscosity to the aqueous systems or coating.

Also, the additives, when used in higher molecular weights, for example750,000 to 2,000,000 g/mol, can act as HASE thickeners with improvedresistance to surfactants and anti-sag properties. Preferably thepolymers of the present invention for use as HASE thickeners haveminimal viscosity reduction in the presence of surfactants.

The anti-settling additives and HASE thickeners of the present inventionrelate to novel polymers comprising a specialized associative monomerthat contains C1-C4 alkyl, for example, C1-C3 alkyl, preferably methylor ethyl, most preferably methyl; propylene oxide; ethylene oxide; and apolymerizable group.

These polymers as anti-settling additives are useful for stains and/orpaints. In wood stains these polymers do not thicken because wood stainshave low viscosity. These polymers are also useful in HASE thickeners.The present invention also includes compositions incorporating suchpolymers as anti-settling additives and/or HASE thickeners and methodsfor use of these polymers to impart anti-settling properties orthickening.

In particular the present invention provides an anti-settling additiveand/or HASE thickener comprising a polymer, the polymer comprising atleast one specialized associative monomer that comprises:

i) at least one polymerizable functional group per molecule; and

ii) at least one polyether radical per molecule according to structure(I):—R¹³—R¹²—R¹¹—  (I)

wherein:

R¹¹ is C1-C4 alkyl, for example C1-C3 alkyl, preferably ethyl or methyl,most preferably methyl

R¹² is absent or is a bivalent linking group, and

R¹³ is according to structure (Villa) or (VIIIb) or (VIIIc):

wherein:

R₄ is independently an alkyl chain containing 1 to about 4 carbon atoms;

R₆ is an alkyl chain containing 1 to about 4 carbon atoms;

M is an integer from 0 to about 50 (preferably about 1 to 50, morepreferably about 5 to 30); N is an integer from 0 to 20 (preferably 1 to20, more preferably 5 to 15); P is an integer from 0 to about 50(preferably 0 to 30); wherein P+M is greater than or equal to 1; whereinQ is an integer from 1 to 4 (typically 1 to 2).

In this description the specialized associative monomers comprise apoly(oxyalkylene) chain connected to an alkyl (hydrophobic) group at oneend and a vinyl polymerizable group at the other end. They are preparedby first ethoxylating and/or propoxylating a linear or branched alkylprimary alcohol to make a surfactant and subsequently reacting theresultant terminal primary hydroxyl group of the ethoxylated and/orpropoxylated chain portion of the surfactant with a vinyl polymerizabledouble bond.

These specialized associative monomers provide a secondary thickeningmechanism when they are used to synthesize HASE thickeners. Additionalthickening is derived from a micelle-like association of hydrophobicmoieties along the polymer backbone. They are also useful asanti-settling agents.

Typically the polymer is characterized by a weight average molecularweight of 1,000 to 5,000,000 g/mol, or 1,000 to 2,000,000 g/mol or10,000 to 1,000,000 g/mol, or 500,000 g/mol to 1,000,000 g/mol.

In a typical embodiment, the polymer as an anti-settling additive has alower limit of weight average molecular weight of about 1,000 or about10,000 g/mol. In a typical embodiment, the polymer as an anti-settlingadditive has a upper limit of weight average molecular weight of about1,200,000 g/mol, or 1,000,000 g/mol, or 750,000 g/mol. or 500,000 g/mol,about 400,000 g/mol or in another embodiment, or about 250,000 g/molorabout 100,000 g/mol. For example, when used as an anti-settling polymerthe polymer has a weight average molecular weight of 1,000 to 1,200,000g/mol or 1,000 to 750,000 g/mol. Typically the anti-settling polymer hasa weight average molecular weight of 10,000 to about 500,000 g/mol.

Generally when used as a HASE polymer (a pH responsive polymer) thepolymer has a lower limit of weight average molecular weight of 750,000g/mol or about 1,000,000 g/mol or about 1,200,000 g/mol. Generally whenused as a HASE polymer (a pH responsive polymer) the polymer has anupper limit of weight average molecular weight of 5,000,000 g/mol orabout 2,000,000 g/mol, or about 900,000 g/mol.

In particular these polymers when used in lower molecular weights, forexample 1,000 to 750,000 g/mol, are useful as anti-settling additivesfor stains or other low viscosity coatings. In wood stains thesepolymers do not thicken because wood stains have low viscosity.

Preferably the specialized associative monomer is an ethlyenicallyunsaturated hydrophobic monomer having the form of structures C.Ia,C.Ib., C.Ic and C.Id:

wherein R₃ is H or CH₃; R₄ is independently an alkyl chain containing 1to about 4 carbon atoms;R₅ is an alkyl chain containing 1 to about 4 carbon atoms, typically analkyl chain containing 1 to 3 carbon atoms, preferably methyl or ethyl,more preferably methyl;R₆ is an alkyl chain containing 1 to about 4 carbon atoms;M is an integer from 0 to about 50 (preferably about 1 to 50, morepreferably about 5 to 30); N is an integer from 0 to 20 (preferably 1 to20, more preferably 5 to 15); P is an integer from 0 to about 50(preferably 0 to 30);wherein P+M is greater than or equal to 1; wherein Q is an integer from1 to 4 (typically 1 to 2).

The present invention also relates to novel HASE polymers comprising thespecialized associative monomer that contains C1-C4 alkyl, typicallyC1-C3, preferably methyl or ethyl, most preferably methyl, propyleneoxide, ethylene oxide and a polymerizable group. The polymers are usefulas thickeners with surfactant resistance.

In one aspect, the anti-settling polymer or HASE polymer is a copolymerof a mixture of unsaturated copolymerizable monomers, the unsaturatedcopolymerizable monomers comprising, based on total weight of monomers:

-   -   A. about 1-70 weight percent, typically 1-40, 5-40, 25-70 or        25-40 wt. % of a polymerizable functional group comprising at        least one C3-C8 alpha beta-ethylenically unsaturated acidic        monomer, preferably comprising a carboxylic acid-functional        substituent group;    -   B. about 15-70 weight percent, typically 20 to 50 wt. % of at        least one nonionic, copolymerizable C2-C12 alpha,        beta-ethylenically unsaturated monomer; and    -   C. about 1 to 30 weight percent, typically 5 to 30 or 5 to 20        wt. % of at least one nonionic ethylenically unsaturated        hydrophobic monomer each independently comprising a compound        according to a structure selected from the group consisting of        structure C.Ia, C.Ib, C.Ic and C.Id:

wherein R₃ is H or CH₃; R₄ is independently an alkyl chain containing 1to about 4 carbon atoms;

R₅ is an alkyl chain containing 1 to about 4 carbon atoms, preferablymethyl or ethyl or propyl, further preferably methyl or ethyl, mostpreferably methyl;

R₆ is an alkyl chain containing 1 to about 4 carbon atoms;

M is an integer from 0 to about 50 (preferably about 1 to 50, morepreferably about 5 to 30); N is an integer from 0 to 20 (preferably 1 to20, more preferably 5 to 15); P is an integer from 0 to about 50(preferably 0 to 30);

wherein P+M is greater than or equal to 1; wherein Q is an integer from1 to 4 (typically 1 to 2).

Optionally, the anti-settling polymer or HASE polymer further comprisesan additional nonionic ethylenically unsaturated hydrophobic monomer,wherein the total of the of at least one hydrophobic monomer ofstructure C1a and structure Clb and the additional nonionicethylenically unsaturated hydrophobic monomer is about 1 to 30 weightpercent based on total weight of monomers of the mixture of unsaturatedcopolymerizable monomers.

In another aspect the present invention relates to compositions such aslow viscosity aqueous dispersions comprising polymers of the presentinvention as an anti-settling additive without thickening. Typical lowviscosity aqueous dispersion products are wood stains. The invention isalso directed to methods of using the pH responsive copolymer as ananti-settling additive for aqueous dispersions, such as wood staincompositions.

In another aspect the present invention relates to methods comprisingresulting from adding the “anti-settling additives” or “anti-settlingagents” to low viscosity pigment suspension agents or particlesuspension agents to coating compositions to help prevent pigments orother finely divided solid particles from settling during storage. Thisis beneficial because depending on the hardness of the settling, it isdifficult, and sometimes not possible, to evenly re-disperse the pigmentand other particles by stirring the solid material throughout theaqueous composition or coating composition. In another aspect thepresent invention relates to compositions resulting from such methods.

Typically, few pigments are dispersed to their ultimate particle size,and coatings and aqueous compositions can contain many aggregates andflocculants. However, the anti-settling additives described hereinmaintain pigment dispersion levels at an adequate level for extendedperiods, allowing coating and aqueous compositions containing pigmentsand fine solid particles to be stored for long periods. In someparticular embodiments, the coating composition is a stain, varnish orlacquer.

In another aspect the present invention relates to compositions such asaqueous dispersions comprising this pH responsive copolymer (also termeda HASE thickener) with surfactant resistance as a thickener. This HASEthickener is useful as a thickener during formulation of the latexbinders, paints and aqueous coatings, compositions for treatingsubterranean formations, home care and personal care. The HASE thickeneradds anti-settling properties with thickening to aqueous compositions orcoating compositions, such as aqueous paints and coatings, personal carecompositions, industrial care and cleaning compositions and compositionsfor use in subterranean formations.

The invention is also directed to methods of using the HASE thickener inthe latex binders, paints and aqueous coatings, compositions fortreating subterranean formations, home care and personal care.

Without being bound by theory, it is believed the improved settlingproperty is due to the soft glassy behavior of the polymer of thepresent invention due to the specialized associative monomer thatcontains a C1-C4 alkyl end group (typically methyl), propylene oxide,ethylene oxide and a polymerizable group, for example a methyl PO-EOmethacrylate monomer.

In one embodiment, the aqueous composition or coating composition is alow viscosity coating having a KU range of less than about 200 KU, lessthan about 100 KU, less than about 80 KU, less than about 75, less thanabout 60 KU, or less than about 50 KU (in certain embodiments).

In one embodiment, the anti-settling additive or HASE thickener is addedin an amount from about 0.5 wt % to about 1 wt % based on the totalweight of the aqueous composition. In another embodiment, theanti-settling additive is added in an amount from about 0.1 wt % toabout 20 wt %, or in other embodiments from about 0.2 wt % to about 10wt %, based on the total weight of the aqueous composition. In yetanother embodiment, the anti-settling additive or HASE thickener isadded in an amount from about 0.4 wt % to about 5 wt % based on thetotal weight of the aqueous composition. In yet another embodiment, theanti-settling additive is added in an amount from about 1 wt % to about20 wt % based on the total weight of the aqueous composition. In yetanother embodiment, the anti-settling additive or HASE thickener isadded in an amount from about 5 wt % to about 20 wt % based on the totalweight of the aqueous composition.

Moreover, the present invention will provide homogeneous, pourableaqueous liquid which improves pigment suspension properties in coatingswithout a significant increase in viscosity as other anti-settlingadditives do. In addition the anti-settling agent and HASE thickener ofthe present invention needs can be incorporated with very low shear intoa formulation. In contrast, other additives are difficult to incorporatein a formulation. For example, in one embodiment, the minimal shearrequired is about 200 rpm (rotations per minute) or greater. In anotherembodiment, the minimal shear required is about 300 rpm (rotations perminute) or greater. In yet another embodiment, the minimal shearrequired is about 400 rpm (rotations per minute) or greater. In yet afurther embodiment, the minimal shear required is about 500 rpm(rotations per minute) or greater.

The aqueous coating compositions including the HASE thickeners of theinvention typically include at least one latex polymer derived from atleast one monomer, for example acrylic monomers. The at least one latexpolymer in the aqueous coating composition can be a pure acrylic, astyrene acrylic, a vinyl acrylic or an acrylated ethylene vinyl acetatecopolymer and is more preferably a pure acrylic. The at least one latexpolymer is preferably derived from at least one acrylic monomer selectedfrom the group consisting of acrylic acid, acrylic acid esters,methacrylic acid, and methacrylic acid esters. For example, the at leastone latex polymer can be a butyl acrylate/methyl methacrylate copolymeror a 2-ethylhexyl acrylate/methyl methacrylate copolymer. Typically, theat least one latex polymer is further derived from one or more monomersselected from the group consisting of styrene, alpha-methyl styrene,vinyl chloride, acrylonitrile, methacrylonitrile, ureido methacrylate,vinyl acetate, vinyl esters of branched tertiary monocarboxylic acids,itaconic acid, crotonic acid, maleic acid, fumaric acid, ethylene, andC4-C8 conjugated dienes.

Latex paint formulations typically comprise additives, e.g., at leastone pigment. In a preferred embodiment of the invention the latex paintformulation includes at least one pigment selected from the groupconsisting of TiO2, CaCO3, clay, aluminum oxide, silicon dioxide,magnesium oxide, sodium oxide, potassium oxide, talc, barytes, zincoxide, zinc sulfite and mixtures thereof. More preferably the at leastone pigment includes TiO2, calcium carbonate or clay.

In addition to the above components, the aqueous coating composition caninclude one or more additives selected from the group consisting ofdispersants, surfactants, rheology modifiers, defoamers, thickeners,biocides, mildewcides, colorants, waxes, perfumes and co-solvents.

Compositions of the present invention may have an absence of one or moreof anionic surfactant, cationic surfactant, nonionic surfactant,zwitterionic surfactant, and/or amphoteric surfactant.

These and other features and advantages of the present invention willbecome more readily apparent to those skilled in the art uponconsideration of the following detailed description, which describe boththe preferred and alternative embodiments of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows Viscosity Profiles of formulations prepared with HASEthickeners containing a (meth)acrylate-[EO]x-[PO]y-CH3 hydrophobicmonomer (in RHOPLEX SG30) for Sample Number 1 without surfactant.

FIG. 2 shows Viscosity Profiles of formulations prepared with HASEthickeners containing a (meth)acrylate-[EO]x-[PO]y-CH3 hydrophobicmonomer (in RHOPLEX SG30) before and after surfactant addition (IGEPALCO887, 1 g).

FIG. 3 shows Viscosity Profiles of formulations prepared with HASEthickeners containing a (meth)acrylate-[EO]x-[PO]y-CH3 hydrophobicmonomer (in RHOPLEX SG30) before and after surfactant addition (IGEPALCO887, 2 g).

FIG. 4 shows Viscosity Profiles of formulations prepared with HASEthickeners containing a (meth)acrylate-[EO]x-[PO]y-CH3 hydrophobicmonomer (in RHOPLEX SG30) before and after surfactant addition (IGEPALCO887, 3 g).

FIG. 5 shows Yield Stress Profiles of formulation prepared with HASEthickeners containing a (meth)acrylate-[EO]x-[PO]y-CH3 hydrophobicmonomer (in RHOPLEX SG30) without surfactant.

FIG. 6 shows Yield Stress Profiles of formulations prepared with HASEthickeners containing a (meth)acrylate-[EO]x-[PO]y-CH3 hydrophobicmonomer (in RHOPLEX SG30) before and after surfactant addition (IGEPALCO887, 2 g).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to anti-settling additives and HASEthickeners of the present invention comprising novel polymers comprisinga specialized hydrophobic associative that contains C1-C4 alkyl, forexample, C1-C3 alkyl, preferably methyl or ethyl, most preferablymethyl, propylene oxide, ethylene oxide and a polymerizable group in amolecular weight rang of 1,000 to 2,000,000 g.mols.

In particular, these anti-settling additives control suspension ofpigment, as well as other fine solids, in coating and aqueouscompositions. It has been surprisingly discovered the additives provideant-settling stability while adding no or little viscosity to theaqueous system or coating. It is desirable in many cases for suchadditives not to impart additional viscosity or to impart very littleviscosity to the aqueous systems or coating. The present invention alsoprovides aqueous compositions for example, aqueous coating compositions,comprising such anti-settling additives and methods of using theanti-settling additives to impart anti-settling properties to an aqueouscomposition.

The present invention also includes compositions, such as paints orother aqueous coating compositions, incorporating such polymers as HASEthickeners when used in higher molecular weights, for example 750,000 to2,000,000 g/mo. These HASE thickeners can provide improved resistance tosurfactants and anti-sag properties. The present invention also providesaqueous compositions for example, aqueous coating compositions,comprising such HASE thickeners and methods of using the HASE thickenersto thicken an aqueous composition.

Thus, HASE thickeners are suitable for use with latex dispersions,binders, paints and coatings. Generally, the aqueous compositions of theinvention for use with HASE thickeners are aqueous polymer dispersionswhich include at least one latex polymer. Paints or other aqueouscoatings of the present invention typically further include at least onepigment. Typically the latex has a Tg of less than −20° C., moretypically less than 5° C., still more typically in the range from 30 to−20° C., e.g., 0° C.

As used herein, the term “alkyl” means a monovalent straight or branchedsaturated hydrocarbon radical, more typically, a monovalent straight orbranched saturated (C₁-C₄₀) hydrocarbon radical, such as, for example,methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl,hexyl, octyl, hexadecyl, octadecyl, eicosyl, behenyl, tricontyl, andtetracontyl.

As used herein, “anti-settling additive” means an additive, as describedherein for example, useful for preventing excessive flocculation (ofpigments, solid or fine particles in an aqueous or coating composition)during storage and/or handling.

As used herein, the term “alkoxyl” means an oxy radical that issubstituted with an alkyl group, such as for example, methoxyl, ethoxyl,propoxyl, isopropoxyl, or butoxyl, which may optionally be furthersubstituted on one or more of the carbon atoms of the radical.

As used herein, the term “alkoxyalkyl” means an alkyl radical that issubstituted with one or more alkoxy substituents, more typically a(C₁-C₂₂)alkyloxy-(C₁-C₆)alkyl radical, such as methoxymethyl, andethoxybutyl.

As used herein, the term “alkenyl” means an unsaturated straight orbranched hydrocarbon radical, more typically an unsaturated straight,branched, (which, in one particular embodiment, is C₁-C₇₅) hydrocarbonradical, that contains one or more carbon-carbon double bonds, such as,for example, ethenyl, n-propenyl, iso-propenyl,

As used herein, terms “aqueous medium” and “aqueous media” are usedherein to refer to any liquid medium of which water is a majorcomponent. Thus, the term includes water per se as well as aqueoussolutions and dispersions.

As used herein, the term “aryl” means an unsaturated hydrocarbon radicalthat contains one or more six-membered carbon rings, more typically asingle six-membered carbon ring, in which the unsaturation may berepresented by three conjugated carbon-carbon double bonds, which may besubstituted one or more of the ring carbons with hydrocarbon, typicallyalkyl or alkenyl, halo, or haloalkyl groups, such as, for example,phenyl, methylphenyl, trimethylphenyl, chlorophenyl,trichloromethylphenyl.

As used herein, the term “arylalkyl” means an alkyl group substitutedwith one or more aryl groups, more typically a (C₁-C₁₈)alkyl substitutedwith one or more (C₆-C₁₄)aryl substituents, such as, for example,phenylmethyl, phenylethyl, and triphenylmethyl.

As used herein, the term “aryloxy” means an oxy radical substituted withan aryl group, such as for example, phenyloxy, methylphenyl oxy,isopropylmethylphenyloxy.

The “bicyclo[d.e.f]” notation is used herein in reference tobicycloheptyl and bicycloheptenyl ring systems in accordance with thevon Baeyer system for naming polycyclic compounds, wherein a bicyclicsystem is named by the prefix “bicyclo-” to indicate number of rings inthe system, followed by a series of three arabic numbers, listed indescending numerical order, separated by full stops, and enclosed insquare brackets, to indicate the respective number of skeletal atoms ineach acyclic chain connecting the two common atoms (the “bridgeheadatoms”), excluding the bridgehead atoms.

A bridgehead atom is any skeletal atom of the ring system bonded tothree or more skeletal atoms (excluding hydrogen). A bicyclic system(which comprises the main ring and main bridge only) is named by: theprefix bicyclo-(indicating the number of rings); numbers indicating thebridge lengths (i.e. number of skeletal atoms excluding the bridgeheadatoms) separated by full stops and placed in square brackets. The threenumbers are cited in decreasing order of size (e.g. [3.2.1]); the nameof the hydrocarbon indicating the total number of skeletal atoms. Forexample, bicyclo[3.2.1]octane is the name for the structure of FormulaI.

As used herein, the terminology “(C_(x)—C_(y))” in reference to anorganic group, wherein x and y are each integers, indicates that thegroup may contain from x carbon atoms to y carbon atoms per group.

As used herein, the term “cycloalkenyl” means an unsaturated hydrocarbonradical, typically an unsaturated (C₅-C₂₂) hydrocarbon radical, thatcontains one or more cyclic alkenyl rings and which may optionally besubstituted on one or more carbon atoms of the ring with one or two(C₁-C₆)alkyl groups per carbon atom, such as cyclohexenyl,cycloheptenyl, and “bicycloalkenyl” means a cycloalkenyl ring systemthat comprises two condensed rings, such as bicycloheptenyl.

As used herein, the term “cycloalkyl” means a saturated or unsaturated(which, in one particular embodiment, is C₁-C₇₅) hydrocarbon radicalthat includes one or more cyclic alkyl rings, such as, for example,cyclopentyl, cycloheptyl, cyclooctyl, and “bicyloalkyl” means acycloalkyl ring system that comprises two condensed rings, such asbicycloheptyl.

As used herein, an indication that a composition is “free” of a specificmaterial means the composition contains no measurable amount of thatmaterial.

As used herein, the term “heterocyclic” means a saturated or unsaturatedorganic radical that comprises a ring or condensed ring system,typically comprising from 4 to 16 ring atoms per ring or ring system,wherein such ring atoms comprise carbon atoms and at least oneheteroatom, such as for example, O, N, S, or P per ring or ring system,which may optionally be substituted on one or more of the ring atoms,such as, for example, thiophenyl, benzothiophenyl, thianthrenyl,pyranyl, benzofuranyl, xanthenyl, pyrrolidinyl, pyrrolyl, pyradinyl,pyrazinyl, pyrimadinyl, pyridazinyl, indolyl, quinonyl, carbazolyl,phenathrolinyl, thiazolyl, oxazolyl, phenoxazinyl, or phosphabenzenyl.

As used herein, the term “hydroxyalkyl” means an alkyl radical, moretypically a (C₁-C₂₂)alkyl radical, that is substituted with one or morehydroxyl groups, such as for example, hydroxymethyl, hydroxyethyl,hydroxypropyl, and hydroxydecyl.

As used herein, the term “halo” means chloro, bromo, iodo, or fluoro.

As used herein, the term “haloalkyl means an alkyl radical (which, inone particular embodiment, is C₁-C₇₅), more typically an alkyl radical,that is substituted on one or more carbon atoms with one or more halogroups, such as, for example, chloromethyl, trichloromethyl.

As used herein, the term “hydroxyalkyl” means an alkyl radical, moretypically an alkyl radical (which, in one particular embodiment, isC₁-C₇₅), that is substituted with one or more hydroxyl groups, such as,for example, hydroxyethyl, hydroxypropyl.

As used herein the term “(meth)acrylate” refers collectively andalternatively to the acrylate and methacrylate and the term“(meth)acrylamide” refers collectively and alternatively to theacrylamide and methacrylamide, so that, for example, “butyl(meth)acrylate” means butyl acrylate and/or butyl methacrylate.

As used herein, “molecular weight” in reference to a polymer or anyportion thereof, means to the weight-average molecular weight (“M_(w)”)of the polymer or portion. M_(w) of a polymer is a value measured by gelpermeation chromatography (GPC) with an aqueous eluent or an organiceluent (for example dimethylacetamide, dimethylformamide, and the like),depending on the composition of the polymer, light scattering (DLS oralternatively MALLS), viscometry, or a number of other standardtechniques. M_(w) of a portion of a polymer is a value calculatedaccording to known techniques from the amounts of monomers, polymers,initiators and/or transfer agents used to make the portion.

In one embodiment, the copolymers for use in the present inventionexhibit a weight average molecular weight, as determined by gelpermeation chromatography (GPC) and light scattering of a solution ofthe polymer in tetrahydrofuran and compared to a polystyrene standard,of greater than or equal to 30,000 grams per mole (“g/mole”). HASEthickeners may not fully dissolve in THF but after hydrolysis they candissolve in water and measurement can be run in a water gel permeationchromatography (GPC). Reference: Macromolecules 2000, 33, 2480. Forexample in a range of 30,000 to 2,000,000 g/mole.

As used herein, each of the terms “monomer”, “polymer”, “homopolymer”,“copolymer”, “linear polymer”, “branched polymer”, “star polymer”, “combpolymer”, “random copolymer”, alternating copolymer”, “block copolymer”,“graft copolymer”, has the meaning ascribed to it in Glossary of basicterms in polymer science (IUPAC Recommendations 1996), Pure Appl. Chem.,Vol. 68, No. 12, pp. 2287-2311, 1996.

As used herein, the indication that a radical may be “optionallysubstituted” or “optionally further substituted” means, in general,unless further limited, either explicitly or by the context of suchreference, such radical may be substituted with one or more inorganic ororganic substituent groups, for example, alkyl, alkenyl, aryl,arylalkyl, alkaryl, a hetero atom, or heterocyclyl, or with one or morefunctional groups capable of coordinating to metal ions, such ashydroxyl, carbonyl, carboxyl, amino, imino, amido, phosphonic acid,sulphonic acid, or arsenate, or inorganic and organic esters thereof,such as, for example, sulphate or phosphate, or salts thereof.

As used herein, “parts by weight” or “pbw” in reference to a namedcompound refers to the amount of the named compound, exclusive, forexample, of any associated solvent. In some instances, the trade name ofthe commercial source of the compound is also given, typically inparentheses. For example, a reference to “10 pbw cocoamidopropylbetaine(“CAPB”, as MIRATAINE BET C-30)” means 10 pbw of the actual betainecompound, added in the form of a commercially available aqueous solutionof the betaine compound having the trade name “MIRATAINE BET C-30”, andexclusive of the water contained in the aqueous solution.

As used herein, an indication that a composition is “substantially free”of a specific material, means the composition contains no more than aninsubstantial amount of that material, and an “insubstantial amount”means an amount that does not measurably affect the desired propertiesof the composition.

As used herein, the term “surfactant” means a compound that reducessurface tension when dissolved in water.

“Surfactant effective amount” means the amount of the surfactant thatprovides a surfactant effect to enhance the stability of emulsions ofthe polymers.

As used herein, suitable polymerizable functional groups include, forexample, acrylo, methacrylo, acrylamido, methacrylamido, diallylamino,allyl ether, vinyl ether, α-alkenyl, maleimido, styrenyl, and α-alkylstyrenyl groups.

I. Anti-Settling Polymer and HASE Polymer

The invention is directed to an anti-settling additive and/or HASEthickener comprising a copolymer of a mixture of unsaturatedcopolymerizable monomers.

In particular the present invention provides an anti-settling additiveand/or HASE thickener comprising a polymer, the polymer comprising atleast one specialized associative monomer that comprises:

i) at least one polymerizable functional group per molecule; and

ii) at least one polyether radical per molecule according to structure(I):—R¹³—R¹²—R¹¹—  (I)

wherein:

R¹¹ is C1-C4 alkyl, for example C1-C3 alkyl, preferably ethyl or methyl,most preferably methyl

R¹² is absent or is a bivalent linking group, and

R¹³ is according to structure (VIIIa), (VIIIb) or (VIIIc):

wherein:

R₄ is independently an alkyl chain containing 1 to about 4 carbon atoms;

R₆ is an alkyl chain containing 1 to about 4 carbon atoms;

M is an integer from 0 to about 50 (preferably about 1 to 50, morepreferably about 5 to 30); N is an integer from 0 to 20 (preferably 1 to20, more preferably 5 to 15); P is an integer from 0 to about 50(preferably 0 to 30); wherein P+M is greater than or equal to 1; whereinQ is an integer from 1 to 4 (typically 1 to 2).

Typically the polymer is characterized by a weight average molecularweight of 1,000 to 5,000,000 g/mol, or 1,000 to 2,000,000 g/mol or10,000 to 1,000,000 g/mol, or 500,000 g/mol to 1,000,000 g/mol.

In a typical embodiment, the polymer as an anti-settling additive has alower limit of weight average molecular weight of about 1,000 or about10,000 g/mol. In a typical embodiment, the polymer as an anti-settlingadditive has a upper limit of weight average molecular weight of about1,200,000 g/mol, or 1,000,000 g/mol, or 750,000 g/mol. or 500,000 g/mol,about 400,000 g/mol or in another embodiment, or about 250,000 g/molorabout 100,000 g/mol. For example, when used as an anti-settling polymerthe polymer has a weight average molecular weight of 1,000 to 1,200,000g/mol or 1,000 to 750,000 g/mol. Typically the anti-settling polymer hasa weight average molecular weight of 10,000 to about 500,000 g/mol.

Generally when used as a HASE polymer (a pH responsive polymer) thepolymer has a lower limit of weight average molecular weight of 750,000g/mol or about 1,000,000 g/mol or about 1,200,000 g/mol. Generally whenused as a HASE polymer (a pH responsive polymer) the polymer has anupper limit of weight average molecular weight of 5,000,000 g/mol orabout 2,000,000 g/mol, or about 900,000 g/mol.

In particular these polymers when used in lower molecular weights, forexample 1,000 to 750,000 g/mol, are useful as anti-settling additivesfor stains or other low viscosity coatings. In wood stains thesepolymers do not thicken because wood stains have low viscosity.

Typically the anti-settling additive is utilized in a coatingcomposition having a viscosity of less than about 200 KU.

Preferably the anti-settling additive is utilized in a coatingcomposition having a viscosity of less than about 100 KU.

In one embodiment, the specialized associative monomer of the presentinvention is according to structure (IX):R¹⁸—R¹³—R¹²—R¹¹  (IX)wherein:R¹¹, R¹², and R¹³ are each defined as above, andR¹⁸ is acrylo, methacrylo, acrylamido, methacrylamido, diallylamino,allyl ether, vinyl ether, α-alkenyl, maleimido, styrenyl, or α-alkylstyrenyl.

In one embodiment, R¹⁸ is acrylo or methacrylo.

Preferably the specialized associative monomer is an ethlyenicallyunsaturated hydrophobic monomer having the form of structure C.Ia, C,Ib,C.Ic or C.Id:

wherein R₃ is H or CH₃;R₄ is independently an alkyl chain containing 1 to about 4 carbon atoms;R₅ is an alkyl chain containing 1 to about 4 carbon atoms, typically analkyl chain containing 1 to 3 carbon atoms, preferably methyl or ethyl,more preferably methyl;R₆ is an alkyl chain containing 1 to about 4 carbon atoms;M is an integer from 0 to about 50 (preferably about 1 to 50, morepreferably about 5 to 30);N is an integer from 0 to 20 (preferably 1 to 20, more preferably 5 to15);P is an integer from 0 to about 50 (preferably 0 to 30); wherein P+M isgreater than or equal to 1;wherein Q is an integer from 1 to 4 (typically 1 to 2).

In one aspect, the anti-settling polymer or HASE polymer is a copolymerof a mixture of unsaturated copolymerizable monomers, the unsaturatedcopolymerizable monomers comprising, based on total weight of monomers:

(I) obtaining a polymer comprising, based on the total weight ofmonomers:

-   -   (a) about 1-70 weight percent, preferably 25 to 70 weight        percent, typically 1-40, 5-40, 25-70 or 25-40 wt. % of a        polymerizable functional group comprising at least one C3-C8        alpha beta-ethylenically unsaturated acidic monomer, preferably        comprising a carboxylic acid-functional substituent group;    -   (b) from about 30 to about 70 percent by weight nonionic        monomeric units, each independently comprising a nonionic        substituent group, preferably copolymerizable C2-C12 alpha,        beta-ethylenically unsaturated monomer, and    -   (c) from about 0.05 to about 20 percent by weight, preferably 1        to 30 percent by weight, typically 5 to 30 or 5 to 20 wt. %        monomeric units, each independently comprising at least one        polyether radical according to structure (I):        —R¹³—R¹²—R¹¹  (I)        wherein:        R¹¹ is C1-C4 alkyl, for example C1-C3 alkyl, preferably ethyl or        methyl, most preferably methyl        R¹² is absent or is a bivalent linking group, and        R¹³ is according to structure (VIIIa) or (VIIIb) or (VIIIc):

wherein:

R₄ is independently an alkyl chain containing 1 to about 4 carbon atoms;R₅ is an alkyl chain containing 1 to 4 carbon atoms, typically an alkylchain containing 1 to 3 carbon atoms, preferably methyl or ethyl orpropyl, further preferably methyl or ethyl, most preferably methyl;

R₆ is an alkyl chain containing 1 to about 4 carbon atoms;

M is an integer from 0 to about 50 (preferably about 1 to 50, morepreferably about 5 to 30); N is an integer from 0 to 20 (preferably 1 to20, more preferably 5 to 15); P is an integer from 0 to about 50(preferably 0 to 30); wherein P+M is greater than or equal to 1; whereinQ is an integer from 1 to 4 (typically 1 to 2).

The anti-settling additive and/or HASE thickener (pH responsivecopolymer) is preferably made from a mixture of unsaturatedcopolymerizable monomers, the unsaturated copolymerizable monomerscomprising, based on total weight of monomers:

-   -   A. about 1-70 weight percent, typically 1-40, 5-40, 25-70 or        25-40 wt. % of a polymerizable functional group comprising at        least one C3-C8 alpha beta-ethylenically unsaturated acidic        monomer, preferably comprising a carboxylic acid-functional        substituent group;    -   B. about 15-70 weight percent, typically 20 to 50 wt. % of at        least one nonionic, copolymerizable C2-C12 alpha,        beta-ethylenically unsaturated monomer; and    -   C. about 1 to 30 weight percent, typically 5 to 30 or 5 to 20        wt. % of at least one nonionic ethylenically unsaturated        hydrophobic monomer each independently comprising a compound        according to a structure selected from the group consisting of        structure C.Ia, C,Ib, C.Ic or C.Id:

wherein R₃ is H or CH₃;R₄ is independently an alkyl chain containing 1 to about 4 carbon atoms;R₅ is an alkyl chain containing 1 to about 4 carbon atoms;R₆ is an alkyl chain containing 1 to about 4 carbon atoms;M is an integer from 1 to about 50 (preferably 5 to 30);N is and integer from 1 to 20 (preferably 5 to 15), P is an integer from0 to about 50 (preferably 0 to 30);Q is an integer from 1 to 4 (typically 1 to 2).

In terms of monomeric units of the resulting anti-settling additive orHASE thickener (pH responsive copolymer), rather than monomers fromwhich the anti-settling additive and/or HASE thickener (pH responsivecopolymer) is made, preferably comprises:

A. about 1-70 weight percent, typically 1-40, 5-40, 25-70 or 25-40weight percent acidic monomeric units derived by opening the alphabeta-ethylenic unsaturated bond of at least one acidic monomer,preferably each acidic monomeric unit independently comprises acarboxylic acid-functional substituent group;

B. about 15-70 weight percent, typically 20 to 50 weight percent,nonionic monomeric units derived by opening an ethylenic unsaturatedbond of at least one copolymerizable nonionic monomer, each comprising anonionic substituent group. The non-ionic monomeric units, eachindependently comprising a nonionic substituent group, for example EthylAcrylate (EA) monomer; and

C. about 1 to 30 weight percent, typically 5 to 30 weight percent ortypically 5 to 20 weight percent, of at least one non-ionicethylenically unsaturated hydrophobic monomeric unit derived by openingan ethylenic unsaturated bond of at least one non-ionic ethylenicallyunsaturated hydrophobic monomer selected from the group consisting ofstructure C.Ia and structure C.Ib (listed above),

wherein R₃ is H or CH₃; R₄ is independently an alkyl chain containing 1to about 4 carbon atoms; R₅ is methyl; R₆ is an alkyl chain containing 1to about 4 carbon atoms; M is an integer from 1 to about 50 (preferably5 to 30); N is and integer from 1 to 20 (preferably 5 to 15), P is aninteger from 0 to about 50 (preferably 0 to 30); wherein Q is an integerfrom 1 to 4 (typically 1 to 2).

The acidic monomeric units provide solubility and anti-sagging property.Typical acidic monomeric units each independently comprise at least oneacid group per monomeric unit, for example, a sulfonic acid group, aphosphonic acid group, a phosphoric acid group, or a carboxylicacid-functional substituent group. Typically the acidic monomeric units,each independently comprise a carboxylic acid-functional substituentgroup, for example, methacrylic acid (MAA).

The nonionic monomeric units, for example slightly insoluble ethylacrylate (EA) or butyl acrylate (BA), segments enhance the thickeningperformance by promoting hydrophobic aggregations.

The hydrophobic macro monomers are responsible for intra-/intermolecularassociations. For example, they are specialty monomers which typicallyinclude a polymerizable group, a hydrophobic macro group and a bivalentpolyether group of a poly(ethylene oxide) chain, usually 5-100 ethyleneoxide units (typically 6-10 EO groups) and optionally 0-5 propyleneoxide units to favor the intermolecular aggregation. The bivalentpolyether group typically links the hydrophobic macro groups to thepolymerizable group. The polymerizable group typically becomes part ofthe backbone of the pH responsive copolymer and the bivalent polyethergroup linking group and macro group becomes a side chain of the pHresponsive copolymer. Examples of this side chain comprising thebivalent polyether group linking group and macro group are abicycloheptyl-polyether group, a bicycloheptenyl-polyether group or abranched (C₅-C₅₀)alkyl-polyether group, wherein thebicycloheptyl-polyether or bicycloheptenyl-polyether group mayoptionally be substituted on one or more ring carbon atoms by one or two(C₁-C₆)alkyl groups per carbon atom.

The invention also provides a method for inhibiting settling ofparticles in an aqueous composition, the method comprising adding thepolymer as an anti-settling additive or HASE thickener to the aqueouscomposition.

In this method, typically the aqueous composition is a coatingcomposition having a viscosity of less than about 200 KU, for example40-50 KU.

Also, typically the aqueous composition is a coating composition havinga viscosity of less than about 100 KU and wherein the polymer has aweight average molecular weight of less than about 250,000 g/mol.

The aqueous composition is typically an aqueous paint compositioncomprising a resin binder, particles selected from the group consistingof pigments, fillers and reflecting agents, and water or awater-miscible solvent.

The invention also provides a polymer for inhibiting settling ofparticles in an aqueous composition comprising:

-   (a) about 25 to about 70 weight percent based on total monomers of    at least one C₃-C₈ alpha beta-ethylenically unsaturated carboxylic    acid monomer of the structure (II):    RCH═C(R′)COOH  (II)

wherein R is H, CH₃, or —CH₂COOX; and wherein if R is H, then R′ is H,C₁-C₄ alkyl, or —CH₂COOX; if R is —C(O)OX, then R′ is H or —CH₂C(O)OX;or if R is CH₃, then R′ is H and X is H or C₁-C₄ alkyl;

-   (b) about 30 to about 70 weight percent based on total monomers of    at least one copolymerizable non-ionic C₂-C₁₂ alpha    beta-ethylenically unsaturated monomer of the structure (III):    CH₂═CYZ  (III)

wherein Y is H, CH₃, or C1; Z is CN, Cl, —COOR′, —C₆H₄R′, —COOR″, or—HC═CH₂; and wherein R is C₁-C₈ alkyl or C₂-C₈ hydroxy alkyl; andwherein R′ is H, Cl, Br, or C₁-C₄ alkyl; and R″ is C₁-C₈ alkyl; and

-   (c) about 0.05 to about 20 weight percent based on total monomer    weight of at least one ethylenically unsaturated monomer represented    by the structure selected from a group consisting of structure (IV)    and structure (VI); wherein structure (IV) is

wherein R is H or CH₃; wherein R₁ is a —(CH₂)_(p)H alkyl chain; whereinp is an integer from 1 to about 4; wherein j is an integer from 1 toabout 50; wherein k is an integer from 0 to about 20, wherein h is 1 or2; and wherein X is a C1-C4 alkyl.

Typically the carboxylic acid monomer a) is selected from a groupconsisting of methacrylic acid, acrylic acid and a combination thereof.Preferably b) is ethyl acrylate.

Typically the polymer is characterized by a weight average molecularweight of 1,000 to 5,000,000 g/mol, or 1,000 to 2,000,000 g/mol or10,000 to 1,000,000 g/mol, or 500,000 g/mol to 1,000,000 g/mol.

In a typical embodiment, the polymer as an anti-settling additive has alower limit of weight average molecular weight of about 1,000 or about10,000 g/mol. In a typical embodiment, the polymer as an anti-settlingadditive has a upper limit of weight average molecular weight of about1,200,000 g/mol, or 1,000,000 g/mol, or 750,000 g/mol. or 500,000 g/mol,about 400,000 g/mol or in another embodiment, or about 250,000 g/molorabout 100,000 g/mol. For example, when used as an anti-settling polymerthe polymer has a weight average molecular weight of 1,000 to 1,200,000g/mol or 1,000 to 750,000 g/mol. Typically the anti-settling polymer hasa weight average molecular weight of 10,000 to about 500,000 g/mol.

In particular these polymers when used in lower molecular weights, forexample 1,000 to 750,000 g/mol, are useful as anti-settling additivesfor stains or other low viscosity coatings. In wood stains thesepolymers do not thicken because wood stains have low viscosity.

Generally when used as a HASE polymer (a pH responsive polymer) thepolymer has a lower limit of weight average molecular weight of 750,000g/mol or about 1,000,000 g/mol or about 1,200,000 g/mol. Generally whenused as a HASE polymer (a pH responsive polymer) the polymer has anupper limit of weight average molecular weight of 5,000,000 g/mol orabout 2,000,000 g/mol, or about 900,000 g/mol.

The invention also provides aqueous compositions containing this polymerand methods of use comprising adding these polymers to an aqueouscomposition.

II. Copolymer as an Anti-Settling Additive or a HASE Thickener

The invention is also directed to an anti-settling additive or a pHresponsive copolymer (HASE thickener) of a mixture of unsaturatedcopolymerizable monomers.

The pH responsive copolymers are substantially insoluble in water at alow pH. However, at higher pH they become swellable or soluble in waterand thus exhibit thickening behavior. Thus, the pH responsive copolymeris interchangeably termed alkali swellable copolymer or alkali solublecopolymer. Typically the pH responsive copolymer is termed ahydrophobically modified alkali-soluble emulsion (HASE) copolymer.Although this copolymer is described as a HASE copolymer it is notnecessary to make a copolymer of this structure by emulsionpolymerization. The copolymer may also be made by solutionpolymerization and comes within the invention whether made by emulsionpolymerization or solution polymerization.

Formula III shows an idealized diagram of the structure of an embodimentof the antisettling additive and/or HASE copolymer (thickener) made frommethacrylic acid as an acidic monomer, ethyl acrylate as the nonionicmonomer, and a hydrophobic monomer. The hydrophobic polymer has apolyethylene oxide polypropylene oxide chain as a bivalent polyethergroup linking a polymerizable functional group and a CH3 hydrophobic endgroup.

Formula IV shows an idealized diagram of the structure of an embodimentof the antisettling additive and/or HASE copolymer (thickener) made fromalpha beta-ethylenic unsaturated bond of mono-[2-(methacryloyloxy)ethyl]phthalate (also known as 2-(2-carboxybenzoyloxy) ethylmethacrylate, MAEP) as a first acidic monomer, methacrylic acid as asecond acidic monomer, ethyl acrylate as the nonionic monomer, and ahydrophobic polymer. The hydrophobic polymer has a polyethyleneoxide-polypropylene oxide chain as a bivalent polyether group linking apolymerizable functional group and a CH3 hydrophobic end group.

Formula V shows an idealized diagram of the structure of theantisettling additive and/or HASE copolymer (thickener) made from alphabeta-ethylenic unsaturated bond of mono-[2-(Methacryloyloxy)ethylhexahydro]phthalate (MAHP) as a first acidic monomer, methacrylic acidas a second acidic monomer, ethyl acrylate as the nonionic monomer, anda hydrophobic polymer. The hydrophobic polymer has a polyethyleneoxide-polypropylene oxide chain as a bivalent polyether group linking apolymerizable functional group and a CH3 hydrophobic end group.

The antisettling additive and/or HASE copolymer (thickener) comprises achain of monomeric units. The polymer is a macromolecule having arelatively high molecular mass that comprises chains of multiplerepetitions of the monomeric units, derived, actually or conceptually,from molecules of relatively low molecular mass and connected to form alinear, branched, or network structure. The copolymer typically has alinear or branched structure, more typically a single strand linear orbranched structure. In one embodiment, a polymer having a predominantlysingle strand linear or branched structure is lightly crosslinked toform a polymer network having a low density of crosslinks. As usedherein the term “single strand” in regard to a polymer means monomericunits of the polymer are connected to join adjacent monomeric units toeach other through two atoms, one on each of the adjacent monomericunits.

The antisettling additive and/or HASE copolymer (thickener) maytypically be regarded as having a “backbone”, or main polymer chain,from which all branches and substituent groups of the polymer may beregarded as being pendant. Where two or more chains of the copolymercould equally be considered to be the main chain of the polymer, thatchain is selected as the main chain which leads to the simplestrepresentation of the polymer molecule. The monomeric units of thecopolymer may be arranged in random, alternating, tapered, or blocksequence along the copolymer chain.

A. Acidic Monomers for pH Responsive Copolymer

The antisettling additive and/or HASE copolymer (thickener) of thepresent invention comprises acidic monomeric units, each independentlycomprising at least one acid group per acidic monomeric unit.

In one embodiment, the acidic monomeric units each independentlycomprise, per monomeric unit, at least one group according to structure(A.I):—R³²—R³¹  (A.I)whereinR³¹ is a moiety that comprises at least one carboxylic acid, sulfonicacid, or phosphoric acid group, andR³² is absent or is a bivalent linking group.

In one embodiment, R³² is O, —(CH₂)_(n)—O—, or is according to structure(structure (A.II):

wherein:

n is an integer of from 1 to 6,

A is O or NR¹⁷, and

R¹⁷ is H or (C₁-C₄)alkyl.

In one embodiment, the acidic monomeric units each independentlycomprise one or two carboxy groups per monomeric unit and may, if theacidic monomeric unit comprises a single carboxy group, further comprisean ester group according to —CH₂COOR³³, wherein R³³ is alkyl, moretypically, (C₁-C₆)alkyl.

The acidic monomeric units may be made by known synthesizing techniques,such as, for example, by grafting of one or more groups according tostructure (A.I) onto a polymer backbone, such as a hydrocarbon polymerbackbone, a polyester polymer backbone, or a polysaccharide polymerbackbone. In the alternative, they may be made by polymerizing a monomercomprising a reactive functional group and at least one group accordingto structure (A.I) per molecule.

In one embodiment, the reactive functional group is an ethylenicallyunsaturated group so the monomer comprising a reactive functional groupis an ethylenically unsaturated monomer. As a result the acidic monomercomprises at least one site of ethylenic unsaturation, more typically,an α-, β-unsaturated carbonyl moiety, and at least one group accordingto structure (A.I) per molecule and is copolymerizable with the nonionicmonomer(s) and the hydrophobic monomer(s).

In one embodiment the acidic monomer comprises one or more ethylenicallyunsaturated monocarboxylic acid monomers according to structure (A.III):R³⁴—R³²—R³¹  (A.III)

wherein:

R³¹ and R³² are each as described above, and

R³⁴ is a moiety having a site of ethylenic unsaturation.

In one embodiment, the compound according to structure (A.III) is an α-,β-unsaturated carbonyl compound. In one embodiment, R³⁴ is according tostructure (A.IV):

wherein R¹⁹ is H or (C₁-C₄)alkyl.

Suitable acidic monomers include, for example, ethylenically unsaturatedcarboxylic acid monomers, such as acrylic acid and methacrylic acid,ethylenically unsaturated dicarboxylic acid monomers, such as maleicacid and fumaric acid, ethylenically unsaturated alkyl monoesters ofdicarboxylic acid monomers, such as butyl methyl maleate, ethylenicallyunsaturated sulphonic acid monomers, such as vinyl sulfonic acid2-acrylamido-2-methylpropane sulfonic acid, and styrene sulfonic acid,and ethylenically unsaturated phosphonic acid monomers, such as vinylphosphonic acid and allyl phosphonic acid, salts of any thereof, andmixtures of any thereof. Alternatively, corresponding ethylenicallyunsaturated anhydride or acid chloride monomers, such as maleicanhydride, may be used and subsequently hydrolyzed to give a pendantmoiety having two acid groups. The preferred acidic monomeric units arederived from one or more monomers selected from acrylic acid,methacrylic acid, and mixtures thereof. Methacrylic acid has thefollowing formula A.V:

In one embodiment, the compound according to structure A.III, inaddition to or in the alternative to the other above discussed acidicmonomers, is an alpha beta-ethylenically unsaturated acidic monomerselected from the group consisting of mono-[2-(methacryloyloxy)ethyl]phthalate (also known as 2-(2-carboxybenzoyloxy) ethylmethacrylate, MAEP) and mono-[2-(Methacryloyloxy)ethylhexahydro]phthalate (MAHP).

Mono-[2-(Methacryloyloxy)ethyl hexahydro]phthalate (MAHP) has thestructure A.VI:

It is commercially available from Wako Pure Chemical Industries.

It has the CAS No. 51252-88-1, the molecular formula C14H20O6, and amolecular weight of 284.31 g/mol.

Mono-[2-(methacryloyloxy) ethyl]phthalate has the structure A.VII:

MAEP has CAS No. 27697-00-3; the chemical formula C14H14O6 and amolecular weight of 278.08 g/mol.

B. Nonionic Ethylenically Unsaturated Monomeric Units for HASE Copolymer

The antisettling additives and/or HASE thickener polymers of the presentinvention may further comprise one or more additional nonionic monomericunits.

In one embodiment, the additional nonionic monomeric units eachindependently comprise, per monomeric unit, at least one group accordingto structure (B.I):—R⁴²—R⁴¹  (B.I)whereinR⁴¹ is alkyl, hydroxyalkyl, alkoxyalkyl, cycloalkyl, aryl, arylalkyl, oraryloxy, andR⁴² is absent or is a bivalent linking group.

In one embodiment, R⁴¹ is (C₁-C₂₂)alkyl, (C₁-C₂₂)hydroxyalkyl,(C₂-C₂₂)alkoxyalkyl, (C₆-C₂₄)cycloalkyl, (C₆-C₄₀)aryl, or(C₇-C₄₀)arylalkyl, more typically (C₂-C₁₂)alkyl.

In one embodiment, R⁴¹ is (C₁-C₂₂)alkyl, more typically, (C₁-C₁₂)alkyl.

In one embodiment, R⁴² is O, —(CH₂)_(n)—O—, wherein n is an integer offrom 1 to 6, or is according to structure (B.II):

wherein:n is an integer of from 1 to 6,A is O or NR¹⁷, and

R¹⁷ is H or (C₁-C₄)alkyl.

The nonionic monomeric units may be made by known synthesizingtechniques, such as, for example, by grafting of one or more groupsaccording to structure (B.I) onto a polymer backbone, such as ahydrocarbon polymer backbone, a polyester polymer backbone, or apolysaccharide polymer backbone, or a backbone made by polymerizationwith, for example, the above described acidic monomers and hydrophobicmonomers, and at least one other monomer selected from monomerscomprising a reactive functional group and at least one group accordingto structure (B.I) per molecule. Alternatively, the nonionic monomericunits may simply be non-grafted portions of a polymer backbone.

In one embodiment, the nonionic monomeric units are derived from anonionic monomer, for example, ethyl acrylate, comprising a reactivefunctional group and a group according to structure (B.I), andcopolymerizable with the acidic monomers and hydrophobic monomers.

In one embodiment, the reactive functional group of the nonionic monomeris an ethylenically unsaturated group and the nonionic monomer is anethylenically unsaturated monomer comprising at least one site ofethylenic unsaturation, more typically, an α-, β-unsaturated carbonylmoiety and at least one group according to structure (B.I) per molecule.

In one embodiment, the nonionic monomer comprises one or more compoundsaccording to structure (B.III):R⁴³—R⁴²—R⁴¹  (B.III)

wherein:

R⁴¹ and R⁴² are each as described above, and

R⁴³ is a moiety having a site of ethylenic unsaturation.

In one embodiment, the compound according to structure (B.IIII) is anα-, β-unsaturated carbonyl compound. In one embodiment, R⁴³ is accordingto structure (B.IV):

wherein R¹⁹ is H or (C₁-C₄)alkyl.

Suitable nonionic monomers include unsaturated monomers containing atleast one group according to structure D.I per molecule, including(meth)acrylic esters such as: methyl (meth)acrylate, ethyl(meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate,cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl(meth)acrylate, lauryl (meth)acrylate isobornyl (meth)acrylate, benzyl(meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl(meth)acrylate, methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate,phenoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, glycidyl(meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl(meth)acrylate, tert-butylaminoethyl (meth)acrylate, and acetoxyethyl(meth)acrylate, (meth)acrylamides such as, (meth)acrylamide, N-methylol(meth)acrylamide, N-butoxyethyl (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-isopropyl (meth)acrylamide, N-tert-butyl(meth)acrylamide, N-tert-octyl (meth)acrylamide, and diacetone(meth)acrylamide, vinyl esters such as vinyl acetate, vinyl propionate,vinyl 2-ethylhexanoate, N-vinylamides such as: N-vinylpyrrolidione,N-vinylcaprolactam, N-vinylformamide, and N-vinylacetamide, and vinylethers such as, methyl vinyl ether, ethyl vinyl ether, butyl vinylether, and hydroxybutyl vinyl ether, and ethylenically unsaturated arylcompounds, such as styrene.

In one embodiment, the anti-settling additive and/or HASE copolymer ofthe present invention is crosslinked. A crosslinked polymer can be madeby, for example, reacting a mixture of hydrophobic monomer, acidicmonomer and nonionic monomer having more than one reactive functionalgroup, such as for example, more than one site of ethylenic unsaturationper molecule. In one embodiment, the nonionic monomer comprises leastone monomeric compound having more than one (meth)acrylic group permolecule, such as, for example, allyl methacrylate, ethylene glycoldimethacrylate, butylene glycol dimethacrylate, diallyl pentaerythritol,methylenebisacrylamide, pentaerythritol di-, tri- and tetra-acrylates,divinyl benzene, polyethylene glycol diacrylates, bisphenol Adiacrylates, butanediol dimethacrylate, 2,2-dimethylpropanedioldimethacrylate, ethylene glycol dimethacrylate, phenylene diacrylate, ora mixture thereof.

Ethylene glycol dimethyl acrylate has the following formula B.IV.

In one embodiment, the polymer of the present invention comprisesnonionic units derived from one or more (C₁-C₂₂)alkyl (meth)acrylicesters, more typically (C₁-C₁₂)alkyl (meth)acrylic esters, such as ethylacrylate, butyl methacrylate, or ethylhexyl acrylate.

C. Nonionic Ethylenically Unsaturated Monomeric Units (AssociativeMonomeric Units) for Anti-Settling Additive or HASE Copolymer

The antisettling additives and/or HASE polymers of the present inventionpreferably comprise one or more nonionic specialized hydrophobicassociative monomeric units derived from a nonionic ethylenicallyunsaturated hydrophobic monomer according to a structure selected fromthe group consisting of structure C.Ia, C.Ib, C.Ic and C.Id:

wherein R₃ is H or CH₃; R₄ is independently an alkyl chain containing 1to about 4 carbon atoms; R₅ is methyl; each R₆ is an alkyl chaincontaining 1 to about 4 carbon atoms; M is an integer from 1 to about 50(preferably 5 to 30); N is and integer from 1 to 20 (preferably 5 to15), P is an integer from 0 to about 50 (preferably 0 to 30); wherein Qis an integer from 1 to 4.

To make a monomer of Structure C.1a, C.Ib, C.Ic or C.Id methanol may bealkoxylated by reacting the methanol with one or more alkylene oxidecompounds, such as ethylene oxide and/or propylene oxide, to form amethyl-polyether intermediate. The alkoxylation may be conductedaccording to well known methods, typically at a temperature in the rangeof about 100° to about 250° C. and at a pressure in the range of fromabout 1 to about 4 bars, in the presence of a catalyst, such as a strongbase, an aliphatic amine, or a Lewis acid, and an inert gas, such asnitrogen or argon.

The methyl-polyether monomer may then be formed from themethyl-polyether intermediate by addition of a moiety containing anethylenically unsaturated group to the methyl-polyether intermediate,by, for example, esterification, under suitable reaction conditions, ofthe methyl-polyether intermediate with, for example, methacrylicanhydride.

Alternatively, a monomer comprising an ethylenically unsaturated group,such as for example, a polyethylene glycol or polypropylene glycolmonomethacrylate, which may optionally be further alkoxylated, may bereacted with the methyl-polyether intermediate to form themethyl-polyether monomer.

Structure (XXII), is an embodiment of the “specialized hydrophobicassociative monomer”:

In this description the specialized associative monomers of structureXXII are prepared by ethoxylating and/or propoxylating a linear orbranched alkyl primary alcohol to make a surfactant and subsequentlyreacting the resultant terminal primary hydroxyl group of theethoxylated and/or propoxylated chain portion of the surfactant with avinyl polymerizable double bond.

For example, the specialized associative monomer according to structure(XXII) can be made as follows: the linear or branched primary alcoholalkoxylated with either ethylene oxide and/or propylene oxide, chargedto a 500 ml round-bottom 5-neck glass flask equipped with a PTFE bladeagitator, temperature sensor, dry compressed air purge line and a watercooled condenser. The liquid ethoxylate/propoxylate is warmed, stirred,and MEHQ is added. A purge of dry air is passed through the liquid andlater methacrylic anhydride is added. The temperature is stabilized andheld between 70-74° C. for five and a half hours. Then the liquid iscooled. Methacrylic acid and water are added and the liquid product isdischarged.

D. Optional Additional Associative Monomers for HASE Copolymer

As stated above, optionally, the anti-settling additive and/or HASEpolymer further comprises an additional nonionic ethylenicallyunsaturated hydrophobic monomer, wherein the total of the specializedassociative monomer of at least one of structure C.1a and structure C.Iband the additional nonionic ethylenically unsaturated associativemonomer is about 1 to 30 weight percent based on total weight ofmonomers of the mixture of unsaturated copolymerizable monomers.

These optional additional associative monomers are ethylenicallyunsaturated associative monomers.

Preferably, the additional associative monomeric units eachindependently comprise, per monomeric unit, at least one branched(C₅-C₅₀)alkyl or bicycloheptyl-polyether or bicycloheptenyl-polyethergroup according to structure (D.I):—R¹⁴—R¹³—R¹²—R¹¹  (D.I).

In one embodiment, R¹¹ is bicyclo[d.e.f]heptyl orbicyclo[d.e.f]heptenyl, wherein d is 2, 3, or 4, e is 1 or 2, f is 0 or1, and the sum of d+e+f=5, and wherein the bicyclo[d.e.f]heptyl orbicyclo[d.e.f]heptenyl may, optionally, be substituted on one or more ofthe ring carbon atoms by one or more (C₁-C₆)alkyl groups,

R¹² is absent or is a bivalent linking group,

R¹³ is bivalent polyether group, and

R¹⁴ is absent or is a bivalent linking group.

Suitable bicycloheptyl- and bicycloheptenyl-moieties may be derivedfrom, for example, terpenic compounds having core (non-substituted) 7carbon atom bicyclic ring systems according to structures (D.II)-(D.VI):

More typically, R¹¹ is:

a bicyclo[2.2.1]heptyl or bicyclo[2.2.1]heptenyl group bonded to R², ifpresent, or to R³, if R² is not present, via its carbon atom at the2-position or 3-position and is typically substituted on its carbon atomat the 7 position by one or two (C₁-C₆)alkyl radicals, more typically bytwo methyl radicals, or

a bicyclo[3.1.1]heptyl or bicyclo[3.1.1]heptenyl group bonded to R², ifpresent, or to R³, if R² is not present, via its carbon atom at the2-position or 3-position and is typically substituted on its carbon atomat the 6-position or 7-position by one or two (C₁-C₆)alkyl radicals,more typically by two methyl radicals.

In another embodiment, R¹¹ is branched (C₅-C₅₀) alkyl group, moretypically a branched alkyl group according to structure (D.VIII):

wherein:

R¹⁵ and R¹⁶ are each independently (C₁-C₄₈)alkyl, and

a is an integer of from 0 to 40,

provided that R¹¹, that is, R¹⁵, R¹⁶ and the —(CH₂)_(a)— radical takentogether, comprises a total of from about 5 to about 50, more typicallyabout 12 to about 50, carbon atoms;

R¹² is absent or is a bivalent linking group,

R¹³ is bivalent polyether group, and

R¹⁴ is absent or is a bivalent linking group.

More typically, R¹² is O, a bivalent hydrocarbon group, even moretypically a methylene group or chain of from 2 to 6 methylene units, ora bivalent alkyleneoxyl group, such as ethyleneoxy. In one embodiment,R¹² is according to structure (D.IX):—(CH₂)_(b)-A-  (D.IX)wherein A is O or absent, and b is an integer of from 1 to 6.

More typically, R¹³ is a bivalent polyether group comprising a linearchain of from 2 to 100 units, each of which may independently be(C₂-C₄)oxyalkylene, more typically, (C₂-C₃)oxyalkylene. In oneembodiment, R¹³ is a bivalent polyether group comprising a chain of from2 to 100 polymerized oxyethylene units and oxypropylene units, which maybe arranged alternately, randomly, or in blocks. In one embodiment, R¹³is a bivalent polyether group comprising a block of polyoxyethyleneunits and a block of oxypropylene units, more typically, a block ofpolyoxyethylene units and a block of oxypropylene units, wherein theblock of oxypropylene units is disposed between and links the block ofoxyethylene units and the R¹² substituent, if present, or the R¹¹substituent, if R¹² is not present.

In one embodiment, R¹³ is according to structure (D.X):

wherein:g and h are independently integers of from 2 to 5, more typically 2 or3,each i is independently an integer of from 1 to about 80, more typicallyfrom 1 to about 50,each j is independently an integer of from 0 to about 80, more typicallyfrom 1 to about 50,k is an integer of from 1 to about 50, provided the product obtained bymultiplying the integer k times the sum of i+j is from 2 to about 100.If i≠0, j≠0, and g≠h, the respective —(C_(p)H_(2p)O)— and—(C_(q)H_(2q)O)— oxylakylene units may be arranged randomly, in blocks,or in alternating order.

In one embodiment,

g=2,

h=3,

i is an integer of from 1 to 50, more typically 10 to 40, and even moretypically from 15 to about 30,

j is an integer of from 1 to 30, more typically from 2 to 20, and evenmore typically from about 2 to about 10, and

k=1.

In one embodiment, R¹⁴ is O, —(CH₂)_(n)—O—, or is according to structure(D.XI):

wherein:

n is an integer of from 1 to 6,

A is O or NR¹⁷, and

R¹⁷ is H or (C₁-C₄)alkyl.

In another embodiment of structure (D.I) R¹¹ is a tri-styryl groupaccording to the following structure D.XII.

wherein R1, R2 and R3 are independently selected from the followingstructures D.XIIa, D.XIIb, D.XIIc, D.XIId.

In one embodiment, the additional associative monomeric units arederived from at least one hydrophobic monomer selected from monomersthat comprise a reactive functional group and at least one groupaccording to structure (D.I) per molecule.

In one embodiment, the reactive functional group of the first monomer isan ethylenically unsaturated group. Thus, the additional associativemonomer is selected from ethylenically unsaturated monomers thatcomprise at least one site of ethylenic unsaturation, more typically anα-, β-unsaturated carbonyl moiety, and least one group according tostructure (D.I) per molecule.

In one embodiment, the additional associative monomer comprises one ormore compounds according to structure (D.XIV):R¹⁸—R¹⁴—R¹³—R¹²—R¹¹  (D.XIV)wherein:

R¹¹, R¹², R¹³, and R¹⁴ are each as described above, and

R¹⁸ is a moiety having a site of ethylenic unsaturation.

In one embodiment, the compound according to structure (D.XIV) is an α-,β-unsaturated carbonyl compound.

In one embodiment, R¹⁸ is according to structure (D.XV):

wherein R¹⁹ is H or (C₁-C₄)alkyl.

In one embodiment, the optional additional associative monomer isselected from monomers according to structure (D.XVI):

wherein:

R¹¹ is bicyclo[d.e.f]heptyl or bicyclo[d.e.f]heptenyl wherein d is 2, 3,or 4, e is 1 or 2, f is 0 or 1, and the sum of d+e+f=5, and which may,optionally, be substituted on one or more of the ring carbon atoms byone or more (C₁-C₆)alkyl groups, or R¹¹ is a tri-styryl group accordingto the above-discussed structure D.XII;

and

R¹⁹, b, g, h, i, j, and k are each as defined above, namely:

R¹⁹ is H or (C₁-C₄)alkyl,

b is an integer of from 1 to 6,

g and h are independently integers of from 2 to 5, more typically 2 or3,

each i is independently an integer of from 1 to about 80, more typicallyfrom 1 to about 50,

each j is independently an integer of from 0 to about 80, more typicallyfrom 1 to about 50,

k is an integer of from 1 to about 50, provided that the productobtained by multiplying the integer k times the sum of i+j is from 2 toabout 100.

Preferably R¹¹ is the bicyclo[d.e.f]heptyl or bicyclo[d.e.f]heptenylgroup.

An example of a suitable embodiment of the optional additionaladditional associative monomers according to structure (D.XVI) whereinR¹¹ is a tri-styryl group according to the structure D.XII and R¹⁹, b,g, h, i, j, and k are each as defined above has structure D.XVIa:

In one embodiment, the optional additional associative monomer comprisesone or more compounds according to structure (D.XVII):

wherein i, j, and R¹⁹ are each as described above, and, more typically,i is an integer of from 10 to 40, and even more typically from 15 toabout 30, or from about 20 to about 30, and j is an integer of from 1 to20, and even more typically from about 2 to about 10. A preferredversion of this structure has the structure D.XVIIa:

In another embodiment, the additional associative monomer comprises oneor more compounds according to structure (D.XVIII):

wherein a, i, j, and R¹⁵, R¹⁶, and R¹⁹ are each as described above.

Suitable additional associative monomer may be made by knownsynthesizing methods. For example, a bicycloheptenyl intermediatecompound (D.XIX), known as “Nopol”:

is made by reacting β-pinene with formaldehyde, and

a bicycloheptyl intermediate compound (D.XX), known as “Arbanol”:

is made by isomerization of α-pinene to camphene and ethoxyhydroxylationof the camphene.

The bicycloheptyl- or bicycloheptenyl-intermediate may then bealkoxylated by reacting the bicycloheptyl- or bicycloheptenylintermediate with one or more alkylene oxide compounds, such as ethyleneoxide or propylene oxide, to form a bicycloheptyl-, orbicycloheptenyl-polyether intermediate. The alkoxylation may beconducted according to well known methods, typically at a temperature inthe range of about 100° to about 250° C. and at a pressure in the rangeof from about 1 to about 4 bars, in the presence of a catalyst, such asa strong base, an aliphatic amine, or a Lewis acid, and an inert gas,such as nitrogen or argon.

The bicycloheptyl-, or bicycloheptenyl-polyether monomer may then beformed from the bicycloheptyl- or bicycloheptenyl-polyether intermediateby addition of a moiety containing an ethylenically unsaturated group tothe bicycloheptyl- or bicycloheptenyl-polyether intermediate, by, forexample, esterification, under suitable reaction conditions, of thebicycloheptyl- or bicycloheptenyl-polyether intermediate with, forexample, methacrylic anhydride.

Alternatively, a monomer comprising a ethylenically unsaturated group,such as for example, a polyethylene glycol monomethacrylate, which mayoptionally be further alkoxylated, may be reacted with thebicycloheptyl- or bicycloheptenyl-intermediate to form thebicycloheptyl-, or bicycloheptenyl-polyether monomer.

In another embodiment, the optional additional associative monomericunits each independently comprise, per monomeric unit, at least onegroup according to structure (D.XXI):—R²³—R²²—R²¹  (D.XXI)wherein:R²¹ is linear or branched (C₅-C₅₀)alkyl, hydroxyalkyl, alkoxyalkyl,aryl, or aryalkyl,R²² is a bivalent polyether group,R²³ is absent or is a bivalent linking group.

In one embodiment, R²¹ is linear or branched (C₅-C₄₀)alkyl, moretypically linear or branched (C₁₀-C₄₀)alkyl, even more typically, linearor branched (C₁₆-C₄₀)alkyl, and still more typically linear or branched(C₁₆-C₃₀)alkyl. In one embodiment, R²¹ is tridecyl, tetradecyl,pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl,heneicosyl, behenyl, tricosyl, tetracosyl, pentacosyl, hexacosyl,heptacosyl, octacosyl, nonacosyl, triacontyl, dotriacontyl,tritriacontyl, tetratriacontyl, pentatriacontyl, hexatriacontyl,heptatriacontyl, octatriacontyl, nonatriacontyl, or tetracontyl, moretypically, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, orbehenyl.

In one embodiment R²¹ is hydroxyalkyl, such as, for example,hydroxyhexadecyl, hydroxyoctadecyl, or hydroxyeicosyl, or alkoxyalkyl,such as for example, methoxyhexadecyl, methoxyoctadecyl, ormethoxyeicosyl.

In one embodiment R²¹ is aryl, such as, for example, phenyl,methylphenyl, methoxyphenyl, dibutylphenyl, triisobutylphenyl, ortristyrylphenyl, or arylalkyl, such as phenylmethyl, phenylethyl, ortriphenylmethyl.

In one embodiment, the optional additional associative monomeric unitseach independently comprise at least one group according to structure(D.XXI) above wherein R²¹ is a linear (C₅-C₅₀)alkyl group.

In one embodiment, the optional additional associative monomeric unitseach independently comprise at least one group according to structure(D.XXI) above wherein R²¹ is a branched (C₅-C₅₀)alkyl group, moretypically a branched (C₅-C₅₀)alkyl group according to structure(D.VIII).

In one embodiment, the optional additional associative monomeric unitscomprise a mixture of hydrophobic monomeric units that eachindependently comprise at least one group according to structure (D.XXI)above wherein R²¹ is a linear (C₅-C₅₀)alkyl group and other hydrophobicmonomeric units that each independently comprise at least one groupaccording to structure (D.XXI) above wherein R²¹ is a branched(C₅-C₅₀)alkyl group, more typically a branched (C₅-C₅₀)alkyl groupaccording to structure (D.VIII) above.

In one embodiment, R²² is a bivalent polyether group comprising a linearchain of from 2 to 100 units, each of which may independently be(C₂-C₄)oxyalkylene, more typically, (C₂-C₃)oxyalkylene. In oneembodiment, R²² is a bivalent polyether group comprising a chain of from2 to 100 polymerized oxyethylene units.

In one embodiment, R²² is according to structure (D.XXII):

wherein:p and q are independently integers of from 2 to 5, more typically 2 or3,each r is independently an integer of from 1 to about 80, more typicallyfrom 1 to about 50,each s is independently an integer of from 0 to about 80, more typicallyfrom 0 to about 50,t is an integer of from 1 to about 50, provided that the productobtained by multiplying the integer t times the sum of r+s is from 2 toabout 100.

If r≠0, s≠0, and p≠q, the respective —(C_(p)H_(2p)O)— and—(C_(q)H_(2q)O)— oxylakylene units may be arranged randomly, in blocks,or in alternating order.

In one embodiment,

p=2,

q=3,

r is an integer of from 1 to 50, more typically 5 to 45, and even moretypically from 10 to about 40,

s is an integer of from 1 to 30, more typically from 2 to 20, and evenmore typically from about 2 to about 10, and

t=1

In another embodiment,

p=2,

r is an integer of from 1 to 50, more typically 5 to 45, and even moretypically from 10 to about 40,

s is 0, and

t=1.

In one embodiment, R²³ is O, —(CH₂)_(p)—O— wherein n is an integer offrom 1 to 6, or is according to structure (D.X) above, wherein A is O orNR¹⁷, and R¹⁷ is H or (C₁-C₄)alkyl.

In one embodiment, the optional additional associative monomeric unitsare derived from copolymerizing at least one monomer that comprises areactive functional group and at least one group according to structure(D.XXI) per molecule.

In one embodiment, the reactive group of the additional associativemonomer is an ethylenically unsaturated group and the monomer is anethylenically unsaturated monomer comprising at least one site ofethylenic unsaturation, more typically, an α-, β-unsaturated carbonylmoiety, and at least one group according to structure (D.XXI) permolecule and copolymerizable with the acidic monomer and the non-ionicmonomer.

In one embodiment, the optional additional associative monomer comprisesone or more compounds according to structure (D.XXIII):R²⁴—R²³—R²²—R²¹  (D.XXIII)wherein:

R²¹, R²², and R²³ are each as described above, and

R²⁴ is a moiety having a site of ethylenic unsaturation. Thus theresulting hydrophobic monomeric unit has the structure (D.XXIV):

In one embodiment, the compound according to structure (D.XXI) is an α-,β-unsaturated carbonyl compound. In one embodiment, R²³ is according tostructure (D.X).

In one embodiment, the additional associative monomer comprises one ormore compounds according to structure (D.XXV):

wherein

R²¹ is linear or branched (C₅-C₅₀)alkyl, hydroxyalkyl, alkoxyalkyl,aryl, or arylalkyl,

R²⁵ is methyl or ethyl, and

p and q are independently integers of from 2 to 5, more typically 2 or3,

each r is independently an integer of from 1 to about 80, more typicallyfrom 1 to about 50,

each s is independently an integer of from 0 to about 80, more typicallyfrom 0 to about 50,

t is an integer of from 1 to about 50, provided that the productobtained by multiplying the integer t times the sum of r+s is from 2 toabout 100; or p, q, r, s, and t are each as otherwise described above.

In one embodiment, the additional associative monomer comprises one ormore compounds according to structure (D.XXV) wherein R²¹ is linear(C₁₆-C₂₂)alkyl.

In one embodiment, the optional additional associative monomer comprisesone or more compounds according to structure (D.XXV) wherein R²¹ is abranched (C₅-C₅₀)alkyl group, more typically a branched (C₅-C₅₀)alkylgroup according to structure (D.VIII). For example R²¹ may have thestructure D.XXVI

wherein m and n each, independently, are positive integers from 1 to 39and m+n represents an integer from 4 to 40, as disclosed by US PatentApplication Publication 2006/02700563 A1 to Yang et al, incorporatedherein by reference.

In one embodiment, the optional additional associative monomer comprisesone or more compounds according to structure (D.XXV) wherein p=2, s=0,and t=1.

In one embodiment, the optional additional associative monomer comprisesone or more compounds according to structure (D.XXV) wherein R²¹ islinear (C₁₆-C₂₂)alkyl, R²⁵ is methyl or ethyl, p=2, s=0, and t=1.

Suitable ethylenically unsaturated optional additional associativemonomers include:

alkyl-polyether (meth)acrylates that comprise at least one linear orbranched (C₅-C₄₀)alkyl-polyether group per molecule, such as hexylpolyalkoxylated (meth)acrylates, tridecyl polyalkoxylated(meth)acrylates, myristyl polyalkoxylated (meth)acrylates, cetylpolyalkoxylated (meth)acrylates, stearyl polyalkoxylated(methyl)acrylates, eicosyl polyalkoxylated (meth)acrylates, behenylpolyalkoxylated (meth)acrylates, melissyl polyalkoxylated(meth)acrylates, tristyrylphenoxyl polyalkoxylated (meth)acrylates, andmixtures thereof,

alkyl-polyether (meth)acrylamides that comprise at least one(C₅-C₄₀)alkyl-polyether substituent group per molecule, such as hexylpolyalkoxylated (meth)acrylamides, tridecyl polyalkoxylated(meth)acrylamides, myristyl polyalkoxylated (meth)acrylamides, cetylpolyalkoxylated (meth)acrylamides, stearyl polyalkoxylated (methyl)acrylamides, eicosyl polyalkoxylated (meth)acrylamides, behenylpolyalkoxylated (meth)acrylamides, melissyl polyalkoxylated(meth)acrylamides and mixtures thereof,

alkyl-polyether vinyl esters, alkyl-polyether vinyl ethers, oralkyl-polyether vinyl amides that comprise at least one(C₅-C₄₀)alkyl-polyether substituent group per molecule such as vinylstearate polyalkoxylate, myristyl polyalkoxylated vinyl ether, andmixtures thereof,

as well as mixtures of any of the above alkyl-polyether acrylates,alkyl-polyether methacrylates, alkyl-polyether acrylamides,alkyl-polyether methacrylamides, alkyl-polyether vinyl esters,alkyl-polyether vinyl ethers, and/or alkyl-polyether vinyl amides.

In one embodiment, the optional additional associative monomer comprisesone or more alkyl-polyalkoxylated (meth)acrylates that comprise onelinear or branched (C₅-C₄₀)alkyl-polyethoxylated group, more typically(C₁₀-C₂₂)alkyl-polyethoxylated group per molecule, such asdecyl-polyethoxylated (meth)acrylates, tridecyl-polyethoxylated(meth)acrylates, myristyl-polyethoxylated (meth)acrylates,cetyl-polyethoxylated (meth)acrylates, stearyl-polyethoxylated(methyl)acrylates, eicosyl-polyethoxylated (meth)acrylates,behenyl-polyethoxylated (meth)acrylates, even more typicallydecyl-polyethoxylated methacrylates, tridecyl-polyethoxylatedmethacrylates, myristyl-polyethoxylated methacrylates,cetyl-polyethoxylated methacrylates, stearyl-polyethoxylatedmethylacrylates, eicosyl-polyethoxylated methacrylates,behenyl-polyethoxylated methacrylates, and mixtures thereof.

In one embodiment the nonionic ethylenically unsaturated additionalassociative monomer comprises a compound according to a structureselected from the group consisting of structure D.XXVIIa, structureD.XXVIIb, structure D.XXVIIc, and structure D.XXVIId:

wherein R₃ is H or CH₃; each R₄ is independently an alkyl chaincontaining 1 to about 4 carbon atoms; R₅ is an alkyl chain containing 5to 6 carbon atoms; R₆ is an alkyl chain containing 1 to about 4 carbonatoms;

M is an integer from 0 to about 50 (preferably about 1 to 50, morepreferably about 5 to 30); N is an integer from 0 to 20 (preferably 1 to20, more preferably 5 to 15); P is an integer from 0 to about 50(preferably 0 to 30); wherein P+M is greater than or equal to 1; whereinQ is an integer from 1 to 4 (typically 1 to 2).

Some typical optional additional associative monomers have any of thestructures D.XXVIII, D.XXIX, D.XXX, or D.XXXI,

III. Making the Anti-Settling Additive and/or HASE Thickener

The anti-settling additive and/or pH responsive HASE copolymer (HASEthickener) is the product of copolymerization of a mixture of monomers,comprising:

-   -   A. about 1-70 weight percent, typically 1-40, 5-40, 25-70 or        25-40 wt. % of a polymerizable functional group comprising at        least one C3-C8 alpha beta-ethylenically unsaturated acidic        monomer, preferably comprising a carboxylic acid-functional        substituent group;    -   B. about 15-70 weight percent, typically 20 to 50 wt. % of at        least one nonionic, copolymerizable C2-C12 alpha,        beta-ethylenically unsaturated monomer; and    -   C. about 1 to 30 weight percent, typically 5 to 30 or 5 to 20        wt. % of at least one nonionic ethylenically unsaturated        specialized associative monomer.

For example, one embodiment of the specialized associative monomercomprises:

i) at least one polymerizable functional group per molecule; and

ii) at least one polyether radical per molecule according to structure(I):—R¹³—R¹²—R¹¹  (I)

wherein:

R¹¹ is C1-C4 alkyl, for example C1-C3 alkyl, preferably ethyl or methyl,most preferably methyl

R¹² is absent or is a bivalent linking group, and

R¹³ is according to structure (VIIIa), (VIIIb) or (VIIIc):

wherein:

R₄ is independently an alkyl chain containing 1 to about 4 carbon atoms;

R₆ is an alkyl chain containing 1 to about 4 carbon atoms;

M is an integer from 0 to about 50 (preferably about 1 to 50, morepreferably about 5 to 30); N is an integer from 0 to 20 (preferably 1 to20, more preferably 5 to 15); P is an integer from 0 to about 50(preferably 0 to 30); wherein P+M is greater than or equal to 1; whereinQ is an integer from 1 to 4 (typically 1 to 2).

In a preferred embodiment the specialized associative monomer comprisesa compound according to a structure selected from the group consistingof structure C.Ia, C.Ib, C.Ic and C.Id:

wherein R₃ is H or CH₃; R₄ is independently an alkyl chain containing 1to about 4 carbon atoms; R₅ is methyl; R₆ is an alkyl chain containing 1to about 4 carbon atoms;

M is an integer from 0 to about 50 (preferably about 1 to 50, morepreferably about 5 to 30); N is an integer from 0 to 20 (preferably 1 to20, more preferably 5 to 15); P is an integer from 0 to about 50(preferably 0 to 30); wherein P+M is greater than or equal to 1; whereinQ is an integer from 1 to 4 (typically 1 to 2).

In one embodiment, the anti-settling additive and/or pH responsive HASEthickener copolymer of the present invention is the product ofpolymerization of a mixture of monomers comprising, based on the 100 pbwof the total amount of the monomers:

-   (a) from about 1, more typically from about 5 or 25 pbw of the first    acidic monomers, to about 70, more typically to about 40 pbw, of a    polymerizable functional group comprising at least one C3-C8 alpha    beta-ethylenically unsaturated acidic monomer,-   (b) from about 15, more typically from about 20 pbw of the one or    more nonionic acidic monomers, to about 70, more typically to about    50 pbw, of at least one nonionic, copolymerizable C2-C12 alpha,    beta-ethylenically unsaturated monomer, and-   (c) from about 1, and more typically from about 5, pbw of the one or    more specialized hydrophobic associative hydrophobic monomers, to    about 30, more typically to about 20, and even more typically to    about 15, pbw of the one or more hydrophobic monomers of structures    C.Ia, C.Ib, C.Ic and C.Id.

Optionally, the anti-settling additive and/or pH responsive HASEthickener polymer further comprises an additional nonionic ethylenicallyunsaturated hydrophobic monomer, wherein the total of the at least onenonionic ethylenically unsaturated associative monomer of structureC.Ia, C.Ib, C.Ic and C.Id and the additional nonionic ethylenicallyunsaturated associative monomer is about 1 to 30 weight percent based ontotal weight of monomers of the mixture of unsaturated copolymerizablemonomers.

The anti-settling additive and/or pH responsive HASE thickener copolymerof the present invention can be conveniently prepared from theabove-described monomers by known aqueous emulsion polymerizationtechniques using free-radical producing initiators, typically in anamount from 0.01 percent to 3 percent, based on the weight of themonomers.

In one embodiment, the polymerization is conducted at a pH of about 5.0or less. Polymerization at an acid pH of about 5.0 or less permitsdirect preparation of an aqueous colloidal dispersion having relativelyhigh solids content without the problem of excessive viscosity.

In one embodiment, the polymerization is conducted in the presence ofone or more free-radical producing initiators selected from peroxygencompounds. Useful peroxygen compounds include inorganic persulfatecompounds such as ammonium persulfate, potassium persulfate, sodiumpersulfate, peroxides such as hydrogen peroxide, organic hydroperoxides,for example, cumene hydroperoxide, and t-butyl hydroperoxide, organicperoxides, for example, benzoyl peroxide, acetyl peroxide, lauroylperoxide, peracetic acid, and perbenzoic acid (sometimes activated by awater-soluble reducing agent such as ferrous compound or sodiumbisulfite), and other free-radical producing materials or techniquessuch as 2,2′-azobisisobutyronitrile and high energy radiation sources.

In one embodiment, the polymerization is conducted in the presence ofone or more emulsifiers. Useful emulsifiers include anionic surfactants,nonionic surfactants, amphoteric surfactants, and zwitterionicsurfactants. In one embodiment, the emulsion polymerization is conductedin the presence of one or more anionic surfactants. Examples of anionicemulsifiers are the alkali metal alkyl aryl sulfonates, the alkali metalalkyl sulfates and the sulfonated alkyl esters. Specific examples ofthese well-known emulsifiers are sodium dodecyl benzene sulfonate,sodium dodecyl butylnaphthalene sulfonate, sodium lauryl sulfate,disodium dodecyl diphenyl ether disulfonate, disodium n-octadecylsulfosuccinamate and sodium dioctyl sulfosuccinate. Known nonionicemulsifiers include, for example, fatty alcohols, alkoxylated fattyalcohols, and alkylpolyglucosides.

The emulsion polymerization may, optionally, be conducted in thepresence, in an amount up to about 10 parts per 100 parts ofpolymerizable monomers, of one or more chain transfer agents.Representative chain transfer agents are carbon tetrachloride,bromoform, bromotrichloromethane, and long-chain alkyl mercaptans andthioesters, such as n-dodecyl mercaptan, t-dodecyl mercaptan, octylmercaptan, tetradecyl mercaptan, hexadecyl mercaptan, butylthioglycolate, isooctyl thioglycolate, and dodecyl thioglycolate.

Optionally, other ingredients well known in the emulsion polymerizationart may be included, such as chelating agents, buffering agents,inorganic salts and pH adjusting agents.

In one embodiment, the polymerization is carried out at a temperaturebetween about 60° C. and 90° C., but higher or lower temperatures may beused. The polymerization can be conducted batchwise, stepwise, orcontinuously with batch and/or continuous addition of the monomers, in aconventional manner.

The monomers can be copolymerized in such proportions, and the resultingemulsion polymers can be physically blended, to give products with thedesired balance of properties for specific applications. For example,for analogous polymers of a given molecular weight, increasing theamount of first monomer tends to increase the yield strength exhibitedby the polymer, increasing the relative amount of second monomer tendsto increase the viscosity of the polymer. One or more fourth monomersmay be added to adjust the properties of the polymer.

These polymeric products prepared by emulsion polymerization at an acidpH are in the form of stable aqueous colloidal dispersions containingthe polymer dispersed as discrete particles having average particlediameters of about 400 to about 3000 Å (40 to 300 nanometers) andpreferably about 600 to about 1750 Å (60 to 175 nanometers), as measuredby light scattering. Dispersions containing polymer particles smallerthan about 400 Å (40 nanometers) are difficult to stabilize, whileparticles larger than about 3000 Å (300 nanometers) reduce the ease ofdispersion in the aqueous products to be thickened.

In one embodiment, the polymer composition is in the form of an aqueouspolymer dispersion, typically having a solids content including thepolymer and any surfactants that may be present and based on the totalweight of the polymer dispersion, of up to about 60 wt % and, moretypically about 20 to about 50 wt %.

Alternatively this (co)polymerization may also be conducted by differentmethods or in different solvents. The scope of methods and solvents iswell known to those skilled in the art.

Thus, these polymers for use in the present invention can be made usingknown solution polymerization techniques, wherein the reactant monomersand initiator are dissolved in an appropriate solvent such as toluene,xylene, tetrahydrofuran, or mixtures thereof. Polymerization can beaccomplished in the time and at the temperature necessary, e.g., 60° C.to 80° C. and about 2 to 24 hours. The polymer product can be isolatedthrough normal separation techniques, including solvent stripping.

In one embodiment, these pH responsive copolymers for use in the presentinvention are in the form of an aqueous colloidal polymer dispersion.When the polymer composition is in the form of an aqueous colloidalpolymer dispersion, the composition is maintained at a pH of about 5 orless to maintain stability. More typically, the aqueous colloidalpolymer dispersion composition has a pH of about 1.5 to about 3. Whenthickening of the composition is desired, the pH of the composition canbe increased to a value above about 5 by addition of a base tosolubilize the polymer.

These HASE copolymers and compositions for use as thickeners in thepresent invention are pH-responsive. At the lower pH levels at which theemulsion polymerization takes place, i.e., pH levels of 5 or less, thecomposition is relatively thin or non-viscous. When the pH of thecopolymer dispersion is neutralized or adjusted by addition of a base toa pH of about 5.5 or more, preferably about 6 to about 11, thecomposition thickens substantially. The composition turns fromsemi-opaque or opaque to translucent or transparent as viscosityincreases. Viscosity increases as copolymer dissolves partially orcompletely in the aqueous phase of the composition. Neutralization canoccur in situ when the emulsion copolymer is blended with the base andadded to the aqueous phase. Or, if desired for a given application,neutralization can be carried out when blending with an aqueous product.Useful bases include, but are not limited to, ammonium hydroxide, anamine, sodium hydroxide, potassium carbonate or the like.

For example, the HASE copolymer having a polymer backbone including MAAand EA is a pH-sensitive thickener. Typically the copolymer is a latexat pH=2.3. When neutralized with a suitable base to a pH above about5.5, the carboxyl groups on the methacrylic acid ionize to carboxylateions. The charge on the polymer induces a conformational change, and thewhite latex becomes water-soluble, thus increasing the hydrodynamicvolume of the polymer. When the HASE copolymers swell, the pendanthydrophobic groups are free to build associations with one another andwith other hydrophobes available in the formulation, such assurfactants, particulates, emulsion droplets and dyes. This phenomenoncreates a network structure that results in a significant viscositybuild.

In contrast to HASE thickeners of the present invention the lowermolecular weight anti-settling additives are generally less pHresponsive.

IV. Uses of the Polymer as Anti-Settling Additive and/or a pH ResponsiveThickener

The polymers and polymer compositions according to the present inventionare useful as anti-settling additives and/or water-soluble pH responsivethickeners for a wide variety of applications ranging from home care,personal care and oilfield drilling fluids.

The anti-settling additives are useful in low viscosity compositionssuch as stains or other low viscosity aqueous coatings. Typical lowviscosities are in the range of at most 200 KU, for example 40-200 KU or40-55 KU.

The thickeners are particularly useful for aqueous paints and coatings.Solution-polymerized polymers can be used in solvent systems oremulsified by known techniques for use in aqueous systems. Other usesinclude latexes and detergents. Useful cosmetic compositions willtypically have an aqueous carrier, a pigment and/or cosmetic active, aHASE emulsion polymer, and optional adjuvants. Useful detergents andcleansers will typically have aqueous carrier, a HASE emulsion polymer,and optional adjuvants. Oilfield drilling fluids will typically have anaqueous carrier, HASE emulsion polymer as a thickener/viscositymodifier, and optional adjuvants. The oilfield drilling fluids areinjected into the oilfield formation. Useful latex coatings willtypically have an aqueous carrier, a HASE emulsion polymer, and optionaladjuvants.

The HASE emulsion polymers according to the present invention asdescribed herein are particularly useful as thickeners for a widevariety of water-based compositions. Such compositions include brine,slurries, and colloidal dispersions of water-insoluble inorganic andorganic materials, such as natural rubber, synthetic or artificiallatexes. The emulsion polymers of the invention are especially useful inareas requiring thickening at neutral pHs, such as in cosmetics.

In one embodiment, the aqueous composition comprising the pH responsivepolymer of the present invention exhibits viscoelastic properties atneutral to alkaline pH values, typically at pH values greater than orequal to about 5, more typically greater than or equal to about 5.5,even more typically from about 6 to about 9.

V. Use of the pH Responsive Polymer With Binders Which Are LatexPolymers

Embodiments of the invention, such as latex paint, may contain more thanone category of latex. There can be a first latex namely, the HASEcopolymer, as a thickener. There can also be a second latex, for exampleRHOPLEX SG30 synthetic latex emulsion resins, as a binder for latexpaint.

Synthetic latexes take the form of aqueous dispersions/suspensions ofparticles of latex polymers. Synthetic latexes include aqueous colloidaldispersions of water-insoluble polymers prepared by emulsionpolymerization of one or more ethylenically unsaturated monomers.Typical of such synthetic latexes are emulsion copolymers ofmonoethylenically unsaturated compounds, such as styrene, methylmethacrylate, acrylonitrile with a conjugated diolefin, such asbutadiene or isoprene; copolymers of styrene, acrylic and methacrylicesters, copolymers of vinyl halide, vinylidene halide, vinyl acetate andthe like. Many other ethylenically unsaturated monomers or combinationsthereof can be emulsion polymerized to form synthetic latexes. Suchlatexes are commonly employed in paints (latex paints) and coatings. Thecomposition of the present invention may be added to latexes tomodify/increase viscosity.

The polymeric thickeners of this invention are advantageous for use withthe water-based compositions according to the foregoing description andwith compositions containing those materials, especially coatingcompositions of various types. Mixtures or combinations of two or morethickeners may be used, if desired. Of course the latex polymers used incoating compositions are preferably film-forming at temperatures about25 degrees C. or less, either inherently or through the use ofplasticizers. Such coating compositions include water-based consumer andindustrial paints; sizing, adhesives and other coatings for paper,paperboard, textiles; and the like.

Latex paints and coatings may contain various adjuvants, such aspigments, fillers and extenders. Useful pigments include, but are notlimited to, titanium dioxide, mica, and iron oxides. Useful fillers andextenders include, but are not limited to, barium sulfate, calciumcarbonate, clays, talc, and silica. The compositions of the presentinvention described herein are compatible with most latex paint systemsand provide highly effective and efficient thickening.

The polymer compositions of the present invention may be added toaqueous product systems at a wide range of amounts depending on thedesired system properties and end use applications. In latex paints, thecomposition is added such that the emulsion (HASE) polymer according tothe present invention is present at about 0.05 to about 5.0 weightpercent and preferably about 0.1 to about 3.0 weight percent based ontotal weight of the latex paint, including all of its components, suchas water, HASE polymer, latex polymer, pigment, and any adjuvants.

The present invention also includes a method of preparing an aqueouscoating composition by mixing together at least one latex polymerderived from at least one monomer and blended with at least one pHresponsive copolymer as described above, and at least one pigment.Preferably, the latex polymer is in the form of latex polymerdispersion. The additives discussed above can be added in any suitableorder to the latex polymer, the pigment, or combinations thereof, toprovide these additives in the aqueous coating composition. In the caseof paint formulations, the aqueous coating composition preferably has apH of from 7 to 10.

In formulating latexes and latex paints/coatings, physical propertiesthat may be considered include, but are not limited to, viscosity versusshear rate, ease of application to surface, spreadability, and shearthinning.

VI. Emulsion Polymerization to Make Latex Binder for Latex Paint

Emulsion polymerization is discussed in G. Pohlein, “EmulsionPolymerization”, Encyclopedia of Polymer Science and Engineering, vol.6, pp. 1-51 (John Wiley & Sons, Inc., NY, N.Y., 1986), the disclosure ofwhich is incorporated herein by reference. Emulsion polymerization is aheterogeneous reaction process in which unsaturated monomers or monomersolutions are dispersed in a continuous phase with the aid of anemulsifier system and polymerized with free-radical or redox initiators.The product, a colloidal dispersion of the polymer or polymer solution,is called a latex.

The monomers typically employed in emulsion polymerization to make latexfor latex paint include such monomers as methyl acrylate, ethylacrylate, methyl methacrylate, butyl acrylate, 2-ethyl hexyl acrylate,other acrylates, methacrylates and their blends, acrylic acid,methacrylic acid, styrene, vinyl toluene, vinyl acetate, vinyl esters ofhigher carboxylic acids than acetic acid, e.g. vinyl versatate,acrylonitrile, acrylamide, butadiene, ethylene, vinyl chloride and thelike, and mixtures thereof. This is further discussed below in thesection entitled “Latex Monomers”.

In the above process, suitable initiators, reducing agents, catalystsand surfactants are well known in the art of emulsion polymerization.Typical initiators include ammonium persulfate (APS), hydrogen peroxide,sodium, potassium or ammonium peroxydisulfate, dibenzoyl peroxide,lauryl peroxide, ditertiary butyl peroxide, 2,2′-azobisisobutyronitrile,t-butyl hydroperoxide, benzoyl peroxide, and the like. Commonly usedredox initiation systems are described e.g., by A. S. Sarac in Progressin Polymer Science 24 (1999), 1149-1204.

Suitable reducing agents are those which increase the rate ofpolymerization and include for example, sodium bisulfite, sodiumhydrosulfite, sodium formaldehyde sulfoxylate, ascorbic acid,isoascorbic acid, and mixtures thereof.

Suitable catalysts are those compounds which increase the rate ofpolymerization and which, in combination with the above-describedreducing agents, promote decomposition of the polymerization initiatorunder the reaction conditions. Suitable catalysts include transitionmetal compounds such as, for example, ferrous sulfate heptahydrate,ferrous chloride, cupric sulfate, cupric chloride, cobalt acetate,cobaltous sulfate, and mixtures thereof.

Emulsion polymerization occurs in the presence of an emulsifier.Typically the mixture contains 0.5 to 6 wt % emulsifier based on weightof latex monomers

Typical emulsifiers are ionic or non-ionic surfactants that arepolymerizable or non-polymerizable in the aqueous coating compositionincluding latex polymer. Suitable ionic and nonionic surfactants arealkyl polyglycol ethers such as ethoxylation products of lauryl,tridecyl, oleyl, and stearyl alcohols; alkyl phenol polyglycol etherssuch as ethoxylation products of octyl- or nonylphenol, diisopropylphenol, triisopropyl phenol; alkali metal or ammonium salts of alkyl,aryl or alkylaryl sulfonates, sulfates, phosphates, and the like,including sodium lauryl sulfate, sodium octylphenol glycolether sulfate,sodium dodecylbenzene sulfonate, sodium lauryldiglycol sulfate, andammonium tritertiarybutyl phenol and penta- and octa-glycol sulfonates,sulfosuccinate salts such as disodium ethoxylated nonylphenol half esterof sulfosuccinic acid, disodium n-octyldecyl sulfosuccinate, sodiumdioctyl sulfosuccinate, and the like.

The polymer latex binder can be produced by first preparing an initiatorsolution comprising the initiator and water. A monomer pre-emulsion isalso prepared comprising one or more surfactants (emulsifiers), andother latex monomers to be used to form the latex polymer, water, andadditional additives such as NaOH.

Thus, a typical process of emulsion polymerization preferably involvescharging water to a reactor and feeding as separate streams apre-emulsion of the monomer and a solution of the initiator. Inparticular, the polymer latex binder can be prepared using emulsionpolymerization by feeding the monomers used to form the latex binder toa reactor in the presence of at least one initiator and at least onesurfactant and polymerizing the monomers to produce the latex binder.Typically the initiator solution and monomer pre-emulsion arecontinuously added to the reactor over a predetermined period of time(e.g. 1.5-5 hours) to cause polymerization of latex monomers to producethe latex polymer.

Prior to the addition of the initiator solution and the monomerpre-emulsion, a seed latex such as a polystyrene seed latex can be addedto the reactor. For example, a small amount of the pre-emulsion and aportion of the initiator may be charged initially at the reactiontemperature to produce “seed” latex. The “seed” latex procedure resultsin better particle-size reproducibility.

Under “normal” initiation conditions, that is initiation conditionsunder which the initiator is activated by heat, the polymerization isnormally carried out at about 60-90° C. A typical “normal” initiatedprocess, for example, could employ ammonium persulfate as initiator at areaction temperature of 80+/−2° C. Under “redox” initiation conditions,namely initiation conditions under which the initiator is activated by areducing agent, the polymerization is normally carried out at 60-70° C.Normally, the reducing agent is added as a separate solution. A typical“redox” initiated process, for example, could employ potassiumpersulfate as the initiator and sodium metabisulfite as the reducingagent at a reaction temperature of 65+/−2° C.

The reactor is operated at desired reaction temperature at least untilall the monomers are fed to produce the polymer latex binder. Once thepolymer latex binder is prepared, it is preferably chemically strippedthereby decreasing its residual monomer content. Preferably, it ischemically stripped by continuously adding an oxidant such as a peroxide(e.g. t-butylhydroperoxide) and a reducing agent (e.g. sodium acetonebisulfite), or another redox pair such as those described by A. S. Saracin Progress in Polymer Science 24 (1999), 1149-1204, to the latex binderat an elevated temperature and for a predetermined period of time (e.g.0.5 hours). The pH of the latex binder can then be adjusted and otheradditives added after the chemical stripping step.

In the above emulsions, the polymer preferably exists as a generallyspherical particle, dispersed in water, with a diameter of about 50nanometers to about 500 nanometers.

For purposes of this description, monomers from which latex polymers maybe derived are termed “latex monomers”.

The latex monomers fed to a reactor to prepare the polymer latex binderpreferably include at least one acrylic monomer selected from the groupconsisting of acrylic acid, acrylic acid esters, methacrylic acid, andmethacrylic acid esters. In addition, the monomers can include styrene,vinyl acetate, or ethylene. The monomers can also include one or moremonomers selected from the group consisting of styrene, (alpha)-methylstyrene, vinyl chloride, acrylonitrile, methacrylonitrile, ureidomethacrylate, vinyl acetate, vinyl esters of branched tertiarymonocarboxylic acids (e.g. vinyl esters commercially available under themark VEOVA from Shell Chemical Company or sold as EXXAR neo vinyl estersby ExxonMobil Chemical Company), itaconic acid, crotonic acid, maleicacid, fumaric acid, and ethylene. It is also possible to include C4-C8conjugated dienes such as 1,3-butadiene, isoprene or chloroprene.Commonly used monomers in making acrylic paints are butyl acrylate,methyl methacrylate, ethyl acrylate and the like. Preferably, themonomers include one or more monomers selected from the group consistingof n-butyl acrylate, methyl methacrylate, styrene and 2-ethylhexylacrylate.

The latex polymer is typically selected from the group consisting ofpure acrylics (comprising acrylic acid, methacrylic acid, an acrylateester, and/or a methacrylate ester as the main monomers); styreneacrylics (comprising styrene and acrylic acid, methacrylic acid, anacrylate ester, and/or a methacrylate ester as the main monomers); vinylacrylics (comprising vinyl acetate and acrylic acid, methacrylic acid,an acrylate ester, and/or a methacrylate ester as the main monomers);and acrylated ethylene vinyl acetate copolymers (comprising ethylene,vinyl acetate and acrylic acid, methacrylic acid, an acrylate ester,and/or a methacrylate ester as the main monomers). The monomers can alsoinclude other main monomers such as acrylamide and acrylonitrile, andone or more functional monomers such as itaconic acid and ureidomethacrylate, as would be readily understood by those skilled in theart. In a particularly preferred embodiment, the latex polymer is a pureacrylic such as a butyl acrylate/methyl methacrylate copolymer derivedfrom monomers including butyl acrylate and methyl methacrylate.

In typical acrylic paint compositions the polymer is comprised of one ormore esters of acrylic or methacrylic acid, typically a mixture, e.g.about 50/50 by weight, of a high T_(g) monomer (e.g. methylmethacrylate) and a low T_(g) monomer (e.g. butyl acrylate), with smallproportions, e.g. about 0.5% to about 2% by weight, of acrylic ormethacrylic acid. The vinyl-acrylic paints usually include vinyl acetateand butyl acrylate and/or 2-ethyl hexyl acrylate and/or vinyl versatate.In vinyl-acrylic paint compositions, at least 50% of the polymer formedis comprised of vinyl acetate, with the remainder being selected fromthe esters of acrylic or methacrylic acid. The styrene/acrylic polymersare typically similar to the acrylic polymers, with styrene substitutedfor all or a portion of the methacrylate monomer thereof.

The latex polymer dispersion preferably includes from about 30 to about75% solids and a mean latex particle size of from about 70 to about 650nm. The latex polymer is preferably present in the aqueous coatingcomposition in an amount from about 5 to about 60 percent by weight, andmore preferably from about 8 to about 40 percent by weight (i.e. theweight percentage of the dry latex polymer based on the total weight ofthe coating composition).

The aqueous coating composition is a stable fluid that can be applied toa wide variety of materials such as, for example, paper, wood, concrete,metal, glass, ceramics, plastics, plaster, and roofing substrates suchas asphaltic coatings, roofing felts, foamed polyurethane insulation; orto previously painted, primed, undercoated, worn, or weatheredsubstrates. The aqueous coating composition of the invention can beapplied to the materials by a variety of techniques well known in theart such as, for example, brush, rollers, mops, air-assisted or airlessspray, electrostatic spray, and the like.

VII. Liquid Carrier

In one embodiment, the composition of the present invention (for examplepaints or stains) comprises the selected polymer and a liquid carrier.

In one embodiment, the liquid carrier is an aqueous carrier comprisingwater and the treatment solution is in the form of a solution, emulsion,or dispersion of the material and additives. In one embodiment, theliquid carrier comprises water and a water miscible organic liquid.Suitable water miscible organic liquids include saturated or unsaturatedmonohydric alcohols and polyhydric alcohols, such as, for example,methanol, ethanol, isopropanol, cetyl alcohol, benzyl alcohol, oleylalcohol, 2-butoxyethanol, and ethylene glycol, as well as alkyletherdiols, such as, for example, ethylene glycol monoethyl ether, propyleneglycol monoethyl ether and diethylene glycol monomethyl ether.

As used herein, terms “aqueous medium” and “aqueous media” are usedherein to refer to any liquid medium of which water is a majorcomponent. Thus, the term includes water per se as well as aqueoussolutions and dispersions.

VIII. Other Additives

As described above, stains, latex paints and coatings may containvarious adjuvants.

The aqueous coating compositions of the invention include less than 2%by weight and preferably less than 1.0% by weight of anti-freeze agentsbased on the total weight of the aqueous coating composition. Forexample, the aqueous coating compositions may be substantially free ofanti-freeze agents.

The aqueous coating composition typically includes at least one pigment.The term “pigment” as used herein includes non-film-forming solids suchas pigments, extenders, and fillers. The at least one pigment ispreferably selected from the group consisting of TiO2 (in both anastaseand rutile forms), clay (aluminum silicate), CaCO3 (in both ground andprecipitated forms), aluminum oxide, silicon dioxide, magnesium oxide,talc (magnesium silicate), barytes (barium sulfate), zinc oxide, zincsulfite, sodium oxide, potassium oxide and mixtures thereof. Suitablemixtures include blends of metal oxides such as those sold under themarks MINEX (oxides of silicon, aluminum, sodium and potassiumcommercially available from Unimin Specialty Minerals), CELITES(aluminum oxide and silicon dioxide commercially available from CeliteCompany), ATOMITES (commercially available from English China ClayInternational), and ATTAGELS (commercially available from Engelhard).More preferably, the at least one pigment includes TiO2, CaCO3 or clay.Generally, the mean particle sizes of the pigments range from about 0.01to about 50 microns. For example, the TiO2 particles used in the aqueouscoating composition typically have a mean particle size of from about0.15 to about 0.40 microns. The pigment can be added to the aqueouscoating composition as a powder or in slurry form. The pigment ispreferably present in the aqueous coating composition in an amount fromabout 5 to about 50 percent by weight, more preferably from about 10 toabout 40 percent by weight.

The coating composition can optionally contain additives such as one ormore film-forming aids or coalescing agents. Suitable firm-forming aidsor coalescing agents include plasticizers and drying retarders such ashigh boiling point polar solvents. Other conventional coating additivessuch as, for example, dispersants, additional surfactants (i.e. wettingagents), rheology modifiers, defoamers, thickeners, additional biocides,additional mildewcides, colorants such as colored pigments and dyes,waxes, perfumes, co-solvents, and the like, can also be used inaccordance with the invention. For example, non-ionic and/or ionic (e.g.anionic or cationic) surfactants can be used to produce the polymerlatex. These additives are typically present in the aqueous coatingcomposition in an amount from 0 to about 15% by weight, more preferablyfrom about 1 to about 10% by weight based on the total weight of thecoating composition.

The aqueous coating composition typically includes less than 10.0% ofanti-freeze agents based on the total weight of the aqueous coatingcomposition. Exemplary anti-freeze agents include ethylene glycol,diethylene glycol, propylene glycol, glycerol (1,2,3-trihydroxypropane),ethanol, methanol, 1-methoxy-2-propanol, 2-amino-2-methyl-1-propanol,and FTS-365 (a freeze-thaw stabilizer from Inovachem SpecialtyChemicals). More preferably, the aqueous coating composition includesless than 5.0% or is substantially free (e.g. includes less than 0.1%)of anti-freeze agents. Accordingly, the aqueous coating composition ofthe invention preferably has a VOC level of less than about 100 g/L andmore preferably less than or equal to about 50 g/L.

The balance of the aqueous coating composition of the invention iswater. Although much of the water is present in the polymer latexdispersion and in other components of the aqueous coating composition,water is generally also added separately to the aqueous coatingcomposition. Typically, the aqueous coating composition includes fromabout 10% to about 85% by weight and more preferably from about 35% toabout 80% by weight water. Stated differently, the total solids contentof the aqueous coating composition is typically from about 15% to about90%, more preferably, from about 20% to about 65%.

The coating compositions are typically formulated such that the driedcoatings comprise at least 10% by volume of dry polymer solids, andadditionally 5 to 90% by volume of non-polymeric solids in the form ofpigments. The dried coatings can also include additives such asplasticizers, dispersants, surfactants, rheology modifiers, defoamers,thickeners, additional biocides, additional mildewcides, colorants,waxes, and the like, that do not evaporate upon drying of the coatingcomposition.

Biocides are substances that kill or inhibit the growth ofmicroorganisms such as bacteria, fungi and algae. Biocides includechlorinated hydrocarbons, organometallics, halogen-releasing compounds,metallic salts, quaternary ammonium compounds, phenolics and organicsulfur compounds.

Exemplary of organic sulfur compounds are compounds based on anisothiazolinone or isothiazolothione structure. The biocidal activity ofthese compounds is effected by inactivation of essential enzymes ofmicrobial metabolism which require sulfhydryl groups for activity. Theseenzymes include phosphoenolpyruvate transphosphorase and a number ofdehydrogenases. The thio moiety of the isothiazolinone orisothiazolothione compounds reacts with the free sulfhydryl groups of anenzyme to form a disulfide bond between the enzyme molecule and theisothiazolinone or isothiazolothione molecule rendering the sulfhydrylunavailable for interaction with substrate or effector molecules.

Isothiazolinone and isothiazolothione biocides have found widespread useas latex preservatives. Most latex emulsions are water based and areprone to microbial attack. Biocides are typically added to the finishedlatex after all processing is completed to protect the latex frommicrobial attack. The present compositions and methods may also includeIsothiazolinone biocides. Biocides which are widely used as latexpreservatives include PROXEL GXL, having an active ingredient of1,2-benzisothiazolin-3-one (BIT), PROMEXAL W50, having an activeingredient of 2-methyl-4,5-trimethylene-4-isothiazolin-3-one, and KATHONLX, a blend of 5-chloro-2-methyl-4-isothiazolin-3-one and2-methyl-4-isothiazolin-3-one active ingredients.

Typical isothiazolinones or isothiazolothiones are represented by thegeneral formula (VI.I):

or a salt or a complex thereof;

wherein X is oxygen or sulfur; R is hydrogen, a substituted orunsubstituted hydrocarbyl group, a substituted or unsubstitutedhydrocarbylthio group, a substituted or unsubstituted hydrocarbyloxygroup or a carbamoyl group; and each of A and D is independentlyhydrogen, a halogen atom, a cyano group, a substituted or unsubstitutedhydrocarbyl group or a direct bond to the other of A or D.

When R, A and D are, or contain, substituted hydrocarbyl groups, thesubstituents are preferably independently halogen, alkoxy or alkylthiowhere the alkyl groups contain 1 to 4 carbon atoms. If R is a carbamoylgroup, preferably it is of the general type —CON(H)(R¹) where R¹ is ahydrogen atom or a hydrocarbyl group, which may be substituted withhalogen, alkoxy or alkylthio substituents. It is generally preferredthat R is a hydrogen atom or a lower alkyl group of 1 to 4 carbon atoms.Most preferably, R is hydrogen or a methyl group.

Preferably, A and D, together with the carbon atoms to which they areattached, form a five- or six-membered substituted or unsubstitutedring. The ring substituents are preferably halogen, alkyl of 1 to 4carbon atoms, alkoxy of 1 to 4 carbon atoms or alkylthio of 1 to 4carbon atoms. The ring may contain a heteroatom such as a nitrogen atomreplacing a carbon atom. Most preferably, A and D form a hydrocarbonring such as benzene, cyclopentene or cyclohexene.

Alternatively, A and D are separate groups. Preferably, at least one ofA and D is not a hydrogen atom and most preferably, at least one of Aand D is a halogen atom or an alkyl group of 1 to 4 carbon atoms.

The biocidal isothiazolinone compounds include5-chloro-2-methyl-4-isothiazolin-3-one (where R is methyl, A is hydrogenand D is chlorine); 2-methyl-4-isothiazolin-3-one (where R is methyl andA and D are both hydrogen); 4,5-dichloro-2-methylisothiazolin-3-one(where R is methyl and A and D are both chlorine);2-n-octylisothiazolin-3-one (where R is n-octyl and A and D are bothhydrogen; 1,2-benzisothiazolin-3-one (where R is hydrogen and A and D,together with the carbon atoms to which they are attached, form abenzene ring); 4,5-trimethylene-4-isothiazolin-3-one (where R ishydrogen and A and D, together with the carbon atoms to which they areattached, form a cyclopentene ring) and2-methyl-4,5-trimethylene-4-isothiazolin-3-one (where R is methyl and Aand D, together with the carbon atoms to which they are attached, form acyclopentene ring).

A typical the biocidal compound of this family which may be used as theadditional biocidal compound in the present invention is one where R ishydrogen and A and D together form an unsubstituted 5- or 6-memberedhydrocarbon ring as in the compounds 1,2-benzisothiazolin-3-one and4,5-trimethylene-4-isothiazolin-3-one.

Certain of the isothiazolinone or isothiazolothione compounds which maybe used as the additional biocidal compound can have improved solubilityin water when ill the form of a salt or complex. The salt or complex maybe with any suitable cation such as an amine (including an alkanolamine)or a metal. Preferably, any metal salt or complex contains a monovalentmetal such as an alkali metal. The alkali metal may be lithium, sodiumor potassium. Most preferably, the alkali metal salt is a sodium salt inview of the ready availability of suitable sodium compounds from whichto prepare the salt.

Certain isothiazolinone or isothiazolothione compounds useful as thebiocidal compounds decompose in the presence of alkali. Exemplary ofalkali-sensitive compounds are 5-chloro-2-methyl-4-isothiazolin-3-oneand 2-methyl-4-isothiazolin-3-one. Accordingly, the pH of thecompositions of the present invention which are alkali sensitive shouldbe maintained at a value no greater than about 8.

IX. Personal Care

The anti-settling additives and/or pH responsive HASE polymer thickenersof the present invention are suitable in the preparation of personalcare (cosmetics, toiletries, health and beauty aids, cosmeceuticals) andtopical health care products, including without limitation, hair careproducts, such as shampoos (including combination shampoos, such as“two-in-one” conditioning shampoos); post-shampoo rinses; setting andstyle maintenance agents including setting aids, such as gels andsprays, grooming aids, such as pomades, conditioners, perms, relaxers,hair smoothing products, and the like; skin care products (facial, body,hands, scalp and feet), such as creams, lotions, conditioners, andcleansing products; anti-acne products; anti-aging products (exfoliant,keratolytic, anticellulite, antiwrinkle, and the like); skin protectantssuch as sunscreens, sunblock, barrier creams, oils, silicones, and thelike; skin color products (whiteners, lighteners, sunless tanningaccelerators, and the like); hair colorants (hair dyes, hair colorrinses, highlighters, bleaches and the like); pigmented skin colorants(face and body makeups, foundation creams, mascara, rouge, lip products,and the like); bath and shower products (body cleansers, body wash,shower gel, liquid soap, soap bars, syndet bars, conditioning liquidbath oil, bubble bath, bath powders, and the like); nail care products(polishes, polish removers, strengtheners, lengtheners, hardeners,cuticle removers, softeners, and the like); and any aqueous acidic tobasic composition to which an effective amount of the hydrophobicpolymer can be incorporated for achieving a beneficial or desirable,physical or chemical, effect therein during storage and/or usage.

In one embodiment, the present invention is directed to a personal carecomposition comprising water, one or more surfactants, and ananti-settling additive and/or a pH responsive HASE polymer thickeneraccording to the present invention.

In one embodiment, the personal care composition comprises, based on 100parts by weight (“pbw”) of the personal care composition, from about 10to about 80 pbw, more typically from about 20 to about 70 pbw, water,from about 1 to about 50 pbw of one or more surfactants and from about0.05 to about 20 pbw of the pH responsive polymer of the presentinvention.

Suitable surfactants include anionic surfactants, cationic surfactants,non-ionic surfactants, zwitterionic surfactants, and mixtures thereof.

Suitable anionic surfactants are known compounds and include, forexample, linear alkylbenzene sulfonates, alpha olefin sulfonates,paraffin sulfonates, alkyl ester sulfonates, alkyl sulfates, alkylalkoxy sulfates, alkyl sulfonates, alkyl alkoxy carboxylates, alkylalkoxylated sulfates, monoalkyl phosphates, dialkyl phosphates,sarcosinates, isethionates, and taurates, as well as mixtures thereof,such as for example, ammonium lauryl sulfate, ammonium laureth sulfate,triethanolamine laureth sulfate, monoethanolamine lauryl sulfate,monoethanolamine laureth sulfate, diethanolamine lauryl sulfate,diethanolamine laureth sulfate, lauric monoglyceride sodium sulfate,sodium lauryl sulfate, sodium laureth sulfate, potassium lauryl sulfate,potassium laureth sulfate, sodium trideceth sulfate, sodium tridecylsulfate, ammonium trideceth sulfate, ammonium tridecyl sulfate, sodiumcocoyl isethionate, disodium laureth sulfosuccinate, sodium methyloleoyl taurate, sodium laureth carboxylate, sodium tridecethcarboxylate, sodium monoalkyl phosphate, sodium dialkyl phosphate,sodium lauryl sarcosinate, lauroyl sarcosine, cocoyl sarcosinate,ammonium cocyl sulfate, sodium cocyl sulfate, potassium cocyl sulfate,monoethanolamine cocyl sulfate, sodium tridecyl benzene sulfonate,sodium dodecyl benzene sulfonate, and mixtures thereof.

The cationic counterion of the anionic surfactant is typically a sodiumcation but may alternatively be a potassium, lithium, calcium,magnesium, ammonium cation, or an alkyl ammonium anion having up to 6aliphatic carbon atoms, such as anisopropylammonium,monoethanolammonium, diethanolammonium, or triethanolammonium cation.Ammonium and ethanolammonium salts are generally more soluble than thesodium salts. Mixtures of the above cations may be used.

Suitable cationic surfactants are known compounds and include, forexample, mono-cationic surfactants according to structure (XX) below:

wherein:

R31, R32, R33 and R34 are independently hydrogen or an organic group,provided that at least one of R31, R32, R33 and R34 is not hydrogen, andX⁻ is an anion, as well as mixtures of such compounds.

If one to three of the R31, R32, R33 and R34 groups are each hydrogen,then the compound may be referred to as an amine salt. Some examples ofcationic amine salts include polyethoxylated (2) oleyl/stearyl amine,ethoxylated tallow amine, cocoalkylamine, oleylamine, and tallow alkylamine.

For quaternary ammonium compounds (generally referred to as quats) R31,R32, R33 and R34 may be the same or different organic group, but may notbe hydrogen. In one embodiment, R31, R32, R33 and R34 are each C8-C24branched or linear hydrocarbon groups which may comprise additionalfunctionality such as, for example, fatty acids or derivatives thereof,including esters of fatty acids and fatty acids with alkoxylated groups;alkyl amido groups; aromatic rings; heterocyclic rings; phosphategroups; epoxy groups; and hydroxyl groups. The nitrogen atom may also bepart of a heterocyclic or aromatic ring system, e.g., cetethylmorpholinium ethosulfate or steapyrium chloride.

Examples of quaternary ammonium compounds of the monoalkyl aminederivative type include: cetyl trimethyl ammonium bromide (also known asCETAB or cetrimonium bromide), cetyl trimethyl ammonium chloride (alsoknown as cetrimonium chloride), myristyl trimethyl ammonium bromide(also known as myrtrimonium bromide or Quaternium-13), stearyl dimethylbenzyl ammonium chloride (also known as stearalkonium chloride), oleyldimethyl benzyl ammonium chloride, (also known as olealkonium chloride),lauryl/myristryl trimethyl ammonium methosulfate (also known ascocotrimonium methosulfate), cetyl dimethyl (2)hydroxyethyl ammoniumdihydrogen phosphate (also known as hydroxyethyl cetyldimoniumphosphate), babassuamidopropalkonium chloride, cocotrimonium chloride,distearyldimonium chloride, wheat germ-amidopropalkonium chloride,stearyl octyldimonium methosulfate, isostearaminopropalkonium chloride,dihydroxypropyl PEG-5 linoleaminium chloride, PEG-2 stearmoniumchloride, Quaternium 18, Quaternium 80, Quaternium 82, Quaternium 84,behentrimonium chloride, dicetyl dimonium chloride, behentrimoniummethosulfate, tallow trimonium chloride and behenamidopropyl ethyldimonium ethosulfate.

Quaternary ammonium compounds of the dialkyl amine derivative typeinclude, for example, distearyldimonium chloride, dicetyl dimoniumchloride, stearyl octyldimonium methosulfate, dihydrogenatedpalmoylethyl hydroxyethylmonium methosulfate, dipalmitoylethylhydroxyethylmonium methosulfate, dioleoylethyl hydroxyethylmoniummethosulfate, hydroxypropyl bisstearyldimonium chloride, and mixturesthereof.

Quaternary ammonium compounds of the imidazoline derivative typeinclude, for example, isostearyl benzylimidonium chloride, cocoyl benzylhydroxyethyl imidazolinium chloride, cocoyl hydroxyethylimidazoliniumPG-chloride phosphate, Quaternium 32, and stearyl hydroxyethylimidoniumchloride, and mixtures thereof.

Typical cationic surfactants comprise dialkyl derivatives such asdicetyl dimonium chloride and distearyldimonium chloride; branchedand/or unsaturated cationic surfactants such asisostearylaminopropalkonium chloride or olealkonium chloride; long chaincationic surfactants such as stearalkonium chloride and behentrimoniumchloride; as well as mixtures thereof.

Suitable anionic counterions for the cationic surfactant include, forexample, chloride, bromide, methosulfate, ethosulfate, lactate,saccharinate, acetate and phosphate anions.

Suitable nonionic surfactants are known compounds and include amineoxides, fatty alcohols, alkoxylated alcohols, fatty acids, fatty acidesters, and alkanolamides. Suitable amine oxides comprise, (C10-C24)saturated or unsaturated branched or straight chain alkyl dimethyloxides or alkyl amidopropyl amine oxides, such as for example, lauramineoxide, cocamine oxide, stearamine oxide, stearamidopropylamine oxide,palmitamidopropylamine oxide, decylamine oxide as well as mixturesthereof. Suitable fatty alcohols include, for example, (C10-C24)saturated or unsaturated branched or straight chain alcohols, moretypically (C.sub.10-C.sub.20) saturated or unsaturated branched orstraight chain alcohols, such as for example, decyl alcohol, laurylalcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, oleylalcohol, linoleyl alcohol and linolenyl alcohol, and mixtures thereof.Suitable alkoxylated alcohols include alkoxylated, typicallyethoxylated, derivatives of (C10-C24) saturated or unsaturated branchedor straight chain alcohols, more typically (C10-C20) saturated orunsaturated branched or straight chain alcohols, which may include, onaverage, from 1 to 22 alkoxyl units per molecule of alkoxylated alcohol,such as, for example, ethoxylated lauryl alcohol having an average of 5ethylene oxide units per molecule. Mixtures of these alkoxylatedalcohols may be used. Suitable fatty acids include (C10-C24) saturatedor unsaturated carboxylic acids, more typically (C10-C22) saturated orunsaturated carboxylic acids, such as, for example, lauric acid, oleicacid, stearic acid, myristic acid, cetearic acid, isostearic acid,linoleic acid, linolenic acid, ricinoleic acid, elaidic acid,arichidonic acid, myristoleic acid, and palmitoleic acid, as well asneutralized versions thereof. Suitable fatty acid esters include estersof (C10-C24) saturated or unsaturated carboxylic acids, more typically(C10-C22) saturated or unsaturated carboxylic acids, for example,propylene glycol isostearate, propylene glycol oleate, glycerylisostearate, and glyceryl oleate, and mixtures thereof. Suitablealkanolamides include aliphatic acid alkanolamides, such as cocamide MEA(coco monoethanolamide) and cocamide MIPA (coco monoisopropanolamide),as well as alkoxylated alkanolamides, and mixtures thereof.

Suitable amphoteric surfactants are known compounds and include forexample, derivatives of aliphatic secondary and tertiary amines in whichthe aliphatic radical can be straight chain or branched and wherein oneof the aliphatic substituents contains from about 8 to about 18 carbonatoms and one contains an anionic water-solubilizing group as well asmixtures thereof. Specific examples of suitable amphoteric surfactantsinclude the alkali metal, alkaline earth metal, ammonium or substitutedammonium salts of alkyl amphocarboxy glycinates and alkylamphocarboxypropionates, alkyl amphodipropionates, alkylamphodiacetates, alkyl amphoglycinates, and alkyl amphopropionates, aswell as alkyl iminopropionates, alkyl iminodipropionates, and alkylamphopropylsulfonates, such as for example, cocoamphoacetatecocoamphopropionate, cocoamphodiacetate, lauroamphoacetate,lauroamphodiacetate, lauroamphodipropionate, lauroamphodiacetate,cocoamphopropyl sulfonate caproamphodiacetate, caproamphoacetate,caproamphodipropionate, and stearoamphoacetate.

In one embodiment, the amphoteric surfactant comprises sodiumlauroampoacetate, sodium lauroampopropionate, disodiumlauroampodiacetate, sodium cocoamphoacetate, disodium cocoamphodiacetateor a mixture thereof.

Suitable Zwitterionic surfactants are known compounds. Any Zwitterionicsurfactant acceptable for use in the intended end use application andchemically stable at the required formulation pH is suitable as theoptional Zwitterionic surfactant component of the composition of thepresent invention, including, for example, those which can be broadlydescribed as derivatives of aliphatic quaternary ammonium, phosphonium,and sulfonium compounds in which the aliphatic radicals can be straightchain or branched and wherein one of the aliphatic substituents containsfrom about 8 to about 24 carbon atoms and one contains an anionicwater-solubilizing group such as carboxyl, sulfonate, sulfate, phosphateor phosphonate. Specific examples of suitable Zwitterionic surfactantsinclude alkyl betaines, such as cocodimethyl carboxymethyl betaine,lauryl dimethyl carboxymethyl betaine, lauryl dimethylalpha-carboxy-ethyl betaine, cetyl dimethyl carboxymethyl betaine,lauryl bis-(2-hydroxy-ethyl)carboxy methyl betaine, stearylbis-(2-hydroxypropyl)carboxymethyl betaine, oleyl dimethylgamma-carboxypropyl betaine, and laurylbis-(2-hydroxypropyl)alpha-carboxyethyl betaine, amidopropyl betaines,and alkyl sultaines, such as cocodimethyl sulfopropyl betaine,stearyldimethyl sulfopropyl betaine, lauryl dimethyl sulfoethyl betaine,lauryl bis-(2-hydroxy-ethyl)sulfopropyl betaine andalkylamidopropylhydroxy sultaines.

In one embodiment, the personal care composition further comprises anelectrolyte, typically in an amount of up to about 20 pbw per 100 pbw ofthe personal care composition. Suitable electrolytes are known compoundsand include salts of multivalent anions, such as potassiumpyrophosphate, potassium tripolyphosphate, and sodium or potassiumcitrate, salts of multivalent cations, including alkaline earth metalsalts such as calcium chloride and calcium bromide, as well as zinchalides, barium chloride and calcium nitrate, salts of monovalentcations with monovalent anions, including alkali metal or ammoniumhalides, such as potassium chloride, sodium chloride, potassium iodide,sodium bromide, and ammonium bromide, alkali metal or ammonium nitrates,and polyelectrolytes, such as uncapped polyacrylates, polymaleates, orpolycarboxylates, lignin sulfonates or naphthalene sulfonateformaldehyde copolymers.

In one embodiment, the personal care composition comprises water, ananionic surfactant, a structuring agent for the anionic surfactant, anda specialized hydrophobic associative polymer of the present inventionas an anti-settling additive and/or a pH responsive HASE thickener andexhibits one or more lamellar surfactant phases. “Lamellar surfactantphases” are phases which comprise one or more surfactant bilayers,typically a plurality of surfactant bilayers separated by liquid medium.Lamellar phases include spherulite phases and the typical form of theliquid crystal G-phase, as well as mixtures thereof. “G-phases”, whichare sometimes referred to in the literature as “L, phases”, aretypically pourable, non-Newtonian, anisotropic products that are cloudylooking and exhibit a characteristic “smeary” appearance on flowing.Lamellar phases can exist in several different forms, including domainsof parallel sheets, which constitute the bulk of the typical G-phasesdescribed above and spherulites formed from a number of concentricspherical shells, each of which is a bilayer of surfactant. In thisspecification the term “G-phase” will be reserved for compositions,which are at least partly of the former type. The spherulites aretypically between 0.1 and 50 microns in diameter and so differfundamentally from micelles. The surfactant phase morphology of thestructured surfactant composition is observed, for example, using anoptical microscope under cross-polarized light at about 40×magnification.

In one embodiment, the personal care composition of the presentinvention exhibits structured surfactant properties, that is,shear-thinning viscosity and a capacity to suspend water insoluble orpartially water soluble components.

As used herein in reference to viscosity, the terminology“shear-thinning” means that such viscosity decreases with an increase inshear rate. Shear-thinning may be characterized as a “non-Newtonian”behavior, in that it differs from that of a classical Newtonian fluid,for example, water, in which viscosity is not dependent on shear rate.

As used herein in reference to a component of an aqueous composition,the terminology “water insoluble or partially water soluble components”means the component is present in the aqueous composition at aconcentration above the solubility limit of the component so, in thecase of a water insoluble component, the component remains substantiallynon-dissolved in the aqueous composition and, in the case of a partiallywater soluble component, at least a portion of such component remainsundissolved in the aqueous composition.

As used herein, characterization of an aqueous composition as “capableof suspending”, or as being “able of suspend” water insoluble orpartially water insoluble components means the composition substantiallyresists flotation of such components in the composition or sinking ofsuch components in such composition so such components appear to beneutrally buoyant in such composition and remain at least substantiallysuspended in such composition under the anticipated processing, storage,and use conditions for such aqueous composition.

In one embodiment, the personal care composition of the presentinvention comprises, based on 100 pbw of the composition from about 5 toabout 40 parts pbw, more typically from about 10 to about 30 pbw, andstill more typically from about 15 to about 25 pbw, of the anionicsurfactant and from about 0.1 to about 25 pbw, more typically, fromabout 0.5 to about 10 pbw, of a structuring agent.

In one embodiment, the pH of the lamellar phase containing personal carecomposition is from about 5.0 to about 7.0, more typically from about5.5 to about 6.5.

Suitable anionic surfactants include those described above. In oneembodiment of the lamellar phase containing personal care composition,the anionic surfactant comprises one or more branched and/or unsaturatedanionic surfactants. Suitable branched anionic surfactants include, forexample, sodium trideceth sulfate, sodium tridecyl sulfate, ammoniumtrideceth sulfate, and ammonium tridecyl sulfate.

Suitable structuring agents include cationic surfactants, amphotericsurfactants, fatty alcohols, alkoxylated alcohols, fatty acids, fattyacid esters, alkanolamides, amine oxides, and electrolytes, and mixturesthereof. An effective amount of such structuring agent is one thatpromotes and/or does not interfere with the formation of a lamellarsurfactant phase. Suitable cationic surfactants, amphoteric surfactants,fatty alcohols, alkoxylated alcohols, fatty acids, fatty acid esters,alkanolamides, amine oxides, and electrolytes are described above.

Typically, the greater the amount of surfactant present in relation toits solubility, the smaller the amount electrolyte that may be requiredin order to form a structure capable of supporting solid materialsand/or to cause flocculation of the structured surfactant. In oneembodiment, the composition contains a sufficient amount of anelectrolyte to promote formation lamellar surfactant phases.

In one embodiment, the personal care composition of the presentinvention further comprises, typically in an amount of from greater than0 pbw to about 50 pbw, more typically from about 1 to about 30 pbw, per100 pbw of the personal care composition, one or more “benefit agents”that is, materials that provide a personal care benefit, such asmoisturizing or conditioning, to the user of the personal carecomposition, such as, for example, emollients, moisturizers,conditioners, polymers, vitamins, abrasives, UV absorbers, antimicrobialagents, anti-dandruff agents, fragrances, and/or appearance modifyingadditives, such as, for example, colored particles or reflectiveparticles, which may be in the form of a solid, liquid, or gas and maybe insoluble or are only partly soluble in the personal carecomposition. Mixtures of the benefit agents may be used.

In one embodiment, the personal care composition is a hair stylingcomposition. Suitable hair styling compositions may be in the form of agel, mousse, or spray and may be applied to the hair and/or skin, forexample, by hand or by spraying, as appropriate in view of the form ofthe composition.

In one embodiment, the personal care composition is a hair styling gelthat comprises a hair styling polymer, a pH responsive polymer of thepresent invention, and a carrier, such as water, a (C2-C6)alkanol, or amixture thereof.

Suitable hair styling polymers typically comprise multiple cationicsites per molecule and include, for example, polyquaternium-11,polyquaternium4, polyquaternium-7, polyquaternium-16, polyquaternium-28,polyquaternium-44, polyquaternium-46, polyquaternium-55,polyquaternium-68 and polyquaternium-88. Suitable hair styling polymersalso include, but are not limited to copolymers of polyvinylpyrrolidone,vinyl acetate, polyvinylcaprolactam, methylether maleic acid,acrylamides, octylacrylamide, butylaminoethyl, crotonic acid,dimethylaminopropyl methacrylate and dimethylaminoethyl methacrylate,and mixtures thereof.

As used herein, the term “mousse” means a composition that is in theform of a foam when applied. In one embodiment, the personal carecomposition is a hair styling mousse is packaged in a pressurizedcontainer and comprises a hair styling polymer, a pH responsive polymerof the present invention, a carrier, such as water, a (C2-C6)alkanol, apropellant suitable for foaming the composition when the composition isdispensed from the container. Suitable propellants are liquefiablegases, such as, for example, propane, butane, isobutane, nitrogen,carbon dioxide, nitrous oxide, 1,2-difluoroethane.

In one embodiment, the personal care composition is a hair spraycomposition suitable for spray application from a container that isequipped with a mechanical sprayer, comprising a hair styling polymer, apH responsive polymer of the present invention, and a carrier, such aswater, a (C2-C6)alkanol, or a mixture thereof.

In one embodiment, the personal care composition is an aerosol hairspray composition suitable for spray application from a pressurizedcontainer and comprises, a hair styling polymer, a carrier, typically a(C1-C6)alkanol or a (C7-C10) isoparaffin, a specialized hydrophobicassociative polymer of the present invention as an anti-settlingadditive or HASE thickener, and a propellant suitable for aerosoldelivery of the hair spray composition to the hair. Suitable propellantsare those described above in regard to the hair styling mousseembodiment of the personal care composition of the present invention.

The hair styling gel, mousse, and hair spray may in each case,optionally further comprise one or more emollients, conditioning agents,shine enhancers, moisture and heat sensitive moieties, or a mixturethereof. Suitable emollients include, for example, PEG-40 castor oil,glycerol, propylene glycol, butylene glycol. Suitable conditioning andshine agents include, for example, quaternized and/or hydrolyzedproteins of honey, soy, wheat, guar or maize, cetyl alcohol, stearylalcohol, ceteareth-20, isopropyl palmitate, cyclopentasiloxane,cyclomethicone, trimethylsilylamodimethicone, phenyltrimethicone,ethoxylated/propylated dimethicone, dimethiconol, panthenol, tocopherolacetate, tocopherol, cetrimmonium chloride, hair keratin and silk aminoacids and ethoxylated/propoxylated waxes of fruit and vegetable origin.

The personal care composition according to the present invention mayoptionally further comprise one or more adjuvants, such as, for example,preservatives such as benzyl alcohol, methyl paraben, propyl paraben andimidazolidinyl urea; pH adjusting agents such as citric acid, succinicacid, phosphoric acid, sodium hydroxide, sodium carbonate; dyes, andsequestering agents such as disodium ethylenediamine tetra-acetate.

In general, personal care compositions may optionally comprise, based on100 pbw of the personal care composition and independently for each suchadjuvant, from about 0 to about 10 pbw, typically from 0.5 pbw to about5.0 pbw, of such optional adjuvants, depending on the desired propertiesof the personal care composition.

X. Use with Materials in Geological Formations

The specialized associative polymer of the present invention as ananti-settling additive or HASE thickener is also useful as a componentin aqueous fluid compositions used in oilfield applications.

In one embodiment, an aqueous fluid composition of the present inventionuseful as a component in aqueous fluid compositions used in oilfieldapplications comprises water and a pH responsive polymer of the presentinvention, typically from about 0.01 to about 40 pbw, more typicallyabout 0.05 to about 40 pbw or 0.1 pbw to 20 pbw, even more typicallyfrom about 1 to about 10 pbw of the pH responsive polymer per 100 pbwcomposition, wherein the pH of the composition is greater than or equalto about 6, more typically, from about 6 to about 10.

A. Fracturing Fluids

In one embodiment, the aqueous fluid composition of the presentinvention is used as the fracturing fluid in a method for hydraulicfracturing of a geologic formation to stimulate the production offluids, such as oil and/or natural gas, from the formation. Thefracturing fluid is injected through a wellbore and against a surface ofthe formation at a pressure and flow rate at least sufficient toinitiate and/or extend one or more fractures in the formation.Typically, the fracturing fluid further comprises a proppant dispersedin the fracturing fluid. Suitable proppants are inorganic particles,such as sand, bauxite particles, or glass beads and are typically in therange of from about 20 to about 40 mesh. Such fracturing fluidcompositions typically contain, based on 100 pbw of the liquid componentof such composition, from about 90 pbw to about 100 pbw water, fromabout 0.1 pbw to about 10 pbw pH responsive polymer, and from about 10pbw to about 150 pbw proppant. The proppant particles are transportedinto fractures in the geologic formation by the pressurized fracturingfluid stream and keep the fractures from closing back down when thestream of fracturing fluid is discontinued. The proppant-filledfractures provide permeable channels through which the formation fluidscan flow to the wellbore and then be withdrawn. Hydraulic fracturingfluids are subject to high temperatures and shear rates.

The polymer and composition of the present invention may be used in thefracturing fluid in an amount of from 0.01 to 5% by weight of the fluid.

1. Crosslinking Agent

A crosslinking agent may be used with the fracturing fluids. Thecrosslinking agents used may include aluminum or antimony or Group 4transition metal compound crosslinking agents. The crosslinking agentmay include zirconium, titanium and hafnium crosslinking agents, andcombinations of these, and may include organo-metallic compounds.Examples of suitable zirconium crosslinking agents include zirconiumtriethanolamine, L-glutamic acid-triethanolamine-zirconium, zirconiumdiethanolamine, zirconium tripropanolamine, and zirconium lactatecomplexes, and/or the related salts, and/or their mixtures. Examples oftitanium crosslinking agents include titanium triethanolamine,dihydroxybis(ammonium lactato)titanium, and titanium acetylacetonate.The crosslinking agent may be included in the fluid in an amount of fromabout 0.01% to about 1.5% by weight of the fluid, more particularly,from about 0.02% to about 0.3% by weight of the fluid.

2. Buffering Agent

A hydroxyl ion releasing agent or buffering agent may be employed toadjust the pH or buffer the fluid, i.e., moderate amounts of either astrong base or acid may be added without causing any large change in pHvalue of the fluid. These may useful in changing the rate ofcrosslinking. Alkaline amine or polyamine compounds that are useful toraise the pH to the desirable level are outlined in U.S. Pat. No.4,579,670, and include tetramethylenediamine, triethylenetetramine,tetraethylenepentamine (TEPA), diethylenetriamine, triethylenediamine,triethylenepentamine, ethylenediamen and similar compounds. The alkalimetal hydroxides, e.g., sodium hydroxide, and carbonates can also beused. Other acceptable materials are Ca(OH)₂, Mg(OH)₂, Bi(OH)₃, Co(OH)₂,Pb(OH)₂, Ni(OH)₂, Ba(OH)₂, and Sr(OH)₂. Acids such as hydrochloric acid,sulfuric acid, nitric acid, citric acid, acetic acid, fumaric acid,maleic acid, can be used to lower the pH.

In various embodiments, the buffering agent is a combination of a weakacid and a salt of the weak acid; an acid salt with a normal salt; ortwo acid salts. Examples of suitable buffering agents are acetic acid-Naacetate; NaH₂PO₄—Na₂PO₄; sodium carbonate-sodium bicarbonate; and sodiumbicarbonate, or other like agents. By employing a buffering agentinstead of merely a hydroxyl ion producing material, a fluid is providedwhich is more stable to a wide range of pH values found in local watersupplies and to the influence of acidic materials located in formationsand the like.

3. Gas Component

The fracturing fluids may contain a gas component, as discussed above.The gas component may be provided from any suitable gas that forms anenergized fluid or foam when introduced into the aqueous medium. See,for example, U.S. Pat. No. 3,937,283 (Blauer et al.), hereinafterincorporated by reference. The gas component may comprise a gas selectedfrom nitrogen, air, argon, carbon dioxide, and any mixtures thereof.Particularly useful are the gas components of nitrogen or carbondioxide, in any quality readily available. The gas component may assistin the fracturing, and also the capacity of the fluid to carry solids,such as proppants. The presence of the gas also enhances the flowback ofthe fluid to facilitate cleanup. The fluid may contain from about 10% toabout 90% volume gas component based upon total fluid volume percent,more particularly from about 20% to about 80% volume gas component basedupon total fluid volume percent, and more particularly from about 30% toabout 70% volume gas component based upon total fluid volume percent.

4. Breaker

Fracturing fluids based on the invention may also comprise a breaker.The purpose of this component is to “break” or diminish the viscosity ofthe fluid so that this fluid is more easily recovered from the formationduring cleanup. With regard to breaking down viscosity, oxidizers,enzymes, or acids may be used. Breakers reduce the polymer's molecularweight by the action of an acid, an oxidizer, an enzyme, or somecombination of these on the polymer itself. The breakers may includepersulfates such as ammonium persulfate, sodium persulfate, andpotassium persulfate, bromates such as sodium bromate and potassiumbromate, periodates, metal peroxides such as calcium peroxide,chlorites, and the like, and the combinations of these breakers, live orencapsulated.

5. Proppant

Embodiments of the invention used as fracturing fluids may also includeproppant particles that are substantially insoluble in the fluids of theformation. Proppant particles carried by the treatment fluid remain inthe fracture created, thus propping open the fracture when thefracturing pressure is released and the well is put into production.Suitable proppant materials include, but are not limited to, sand,walnut shells, sintered bauxite, glass beads, ceramic materials,naturally occurring materials, or similar materials. Mixtures ofproppants can be used as well. If sand is used, it will typically befrom about 20 mesh (0.841 mm) to about 100 mesh (0.0059 mm) in size.With synthetic proppants, mesh sizes of about 8 (0.937 mm) or greatermay be used. Naturally occurring materials may be underived and/orunprocessed naturally occurring materials, as well as materials based onnaturally occurring materials that have been processed and/or derived.Suitable examples of naturally occurring particulate materials for useas proppants include, but are not necessarily limited to: ground orcrushed shells of nuts such as walnut, coconut, pecan, almond, ivorynut, brazil nut, etc.; ground or crushed seed shells (including fruitpits) of seeds of fruits such as plum, olive, peach, cherry, apricot,etc.; ground or crushed seed shells of other plants such as maize (e.g.,corn cobs or corn kernels), etc.; processed wood materials such as thosederived from woods such as oak, hickory, walnut, poplar, mahogany, etc.including such woods that have been processed by grinding, chipping, orother form of particalization, processing, etc. Further information onnuts and composition thereof may be found in Encyclopedia of ChemicalTechnology, Edited by Raymond E. Kirk and Donald F. Othmer, ThirdEdition, John Wiley & Sons, Volume 16, pages 248-273 (entitled “Nuts”),Copyright 1981, which is incorporated herein by reference.

The concentration of proppant in the fluid can be any concentrationknown in the art, and will preferably be in the range of from about 0.03to about 3 kilograms of proppant added per liter of liquid phase. Also,any of the proppant particles can further be coated with a resin topotentially improve the strength, clustering ability, and flow backproperties of the proppant.

6. Aqueous Media

The aqueous medium of the fracturing fluids of the present invention maybe water or brine. In those embodiments of the invention where theaqueous medium is a brine, the brine is water comprising an inorganicsalt or organic salt. Inorganic salts may include alkali metal halides,such as potassium chloride. The carrier brine phase may also comprise anorganic salt, such as sodium or potassium formate. Inorganic divalentsalts include calcium halides, such as calcium chloride or calciumbromide. Sodium bromide, potassium bromide, or cesium bromide may alsobe used. The salt may be chosen for compatibility reasons i.e. where thereservoir drilling fluid used a particular brine phase and thecompletion/clean up fluid brine phase is chosen to have the same brinephase. Typical salt levels are 2 to 30 wt % salt based on overallcomposition of the aqueous brine. The most common level of salt in brineis 2-10 weight % sodium chloride, potassium chloride or mixtures thereofbased on overall composition of the aqueous brine.

7. Fiber Component

A fiber component may be included in the fracturing fluids of theinvention to achieve a variety of properties including improvingparticle suspension, and particle transport capabilities, and gas phasestability. Fibers used may be hydrophilic or hydrophobic in nature, buthydrophilic fibers may be useful for some applications. Fibers can beany fibrous material, such as, but not necessarily limited to, naturalorganic fibers, comminuted plant materials, synthetic polymer fibers (bynon-limiting example polyester, polyaramide, polyamide, novoloid or anovoloid-type polymer), fibrillated synthetic organic fibers, ceramicfibers, inorganic fibers, metal fibers, metal filaments, carbon fibers,glass fibers, ceramic fibers, natural polymer fibers, and any mixturesthereof. Particularly useful fibers are polyester fibers coated to behighly hydrophilic, such as, but not limited to, DACRON polyethyleneterephthalate (PET) fibers available from Invista Corp. Wichita, Kans.,USA, 67220. Other examples of useful fibers include, but are not limitedto, polylactic acid polyester fibers, polyglycolic acid polyesterfibers, polyvinyl alcohol fibers, and the like. When used in fluids ofthe invention, the fiber component may be include at concentrations fromabout 1 to about 15 grams per liter of the liquid phase of the fluid, incertain applications the concentration of fibers may be from about 2 toabout 12 grams per liter of liquid, and in others from about 2 to about10 grams per liter of liquid.

8. Other Optional Ingredients

Fluid embodiments of fracturing fluids of the invention may furthercontain other additives and chemicals that are known to be commonly usedin oilfield applications by those skilled in the art. These include, butare not necessarily limited to, materials such as surfactants inaddition to those mentioned herein, clay stabilizers such as tetramethylammonium chloride and/or potassium chloride, breaker aids in addition tothose mentioned herein, oxygen scavengers, alcohols, scale inhibitors,corrosion inhibitors, fluid-loss additives, bactericides, and the like.Also, they may include a co-surfactant to optimize viscosity or tominimize the formation of stable emulsions that contain components ofcrude oil or a polysaccharide or chemically modified polysaccharide,polymers such as cellulose, derivatized cellulose, guar gum, derivatizedguar gum, xanthan gum, or synthetic polymers such as polyacrylamides andpolyacrylamide copolymers, oxidizers such as ammonium persulfate andsodium bromate, and biocides such as 2,2-dibromo-3-nitrilopropionamine.The fluid should be substantially devoid of hectorite clay or other claycomponents and such components may be present in the fluid only inamounts of less than 0.1% by weight.

Aqueous fluid embodiments of the invention may also comprise anorganoamino compound. Examples of suitable organoamino compoundsinclude, but are not necessarily limited to, tetraethylenepentamine(TEPA), triethylenetetramine, pentaethylenehexamine, triethanolamine,and the like, or any mixtures thereof. When organoamino compounds areused in fluids of the invention, they are incorporated at an amount fromabout 0.01 wt % to about 2.0 wt % based on total liquid phase weight.The organoamino compound may be incorporated in an amount from about0.05 wt % to about 1.0 wt % based on total weight of the fluid. Aparticularly useful organoamino compound is tetraethylenepentamine(TEPA).

9. Hydraulic Fracturing Techniques

The fluids of the invention may be used for hydraulically fracturing asubterranean formation. Techniques for hydraulically fracturing asubterranean formation are known to persons of ordinary skill in theart, and involve pumping the fracturing fluid into the borehole and outinto the surrounding formation. The fluid pressure is above the minimumin situ rock stress, thus creating or extending fractures in theformation. See Stimulation Engineering Handbook, John W. Ely, PennwellPublishing Co., Tulsa, Okla. (1994), U.S. Pat. No. 5,551,516 (Normal etal.), “Oilfield Applications”, Encyclopedia of Polymer Science andEngineering, vol. 10, pp. 328-366 (John Wiley & Sons, Inc. New York,N.Y., 1987) and references cited therein, the disclosures of which areincorporated herein by reference thereto.

In the fracturing treatment, fluids of the present invention may be usedin the pad treatment, the proppant stages, or both. The components ofthe liquid phase may be mixed on the surface. Alternatively, the fluidmay be prepared on the surface and pumped down tubing while any gascomponent could be pumped down the annulus to mix down hole, or viceversa.

In hydraulic fracturing the fracturing fluid comprising water solublepolymer and at least one nonionic surfactant is pumped into the targetedformation at a rate in excess of what can be dissipated through thenatural permeability of the formation rock. The fracturing fluids resultin a pressure build up until such pressure exceeds the strength of theformation rock. When this occurs, the formation rock fails and aso-called “fracture” is initiated. With continued pumping, the fracturegrows in length, width and height.

At a predetermined time in the pumping process, solid particulate istypically added to the fluid that is being pumped. This particulate iscarried down the well, out of the wellbore and deposited in the createdfracture. It is the purpose of this specially designed particulate tokeep the fracture from “healing” to its initial position (after pumpinghas ceased). The particulate is said to be propping open the fractureand is therefore designated as “proppant”. The fracture, which isgenerated by the application of this stimulation technique, creates aconductive path to the wellbore for the hydrocarbon.

Typical proppant is selected from the group consisting of gravel, quartzsand grains, sintered bauxite, glass and ceramic beads, walnut shellfragments, or aluminum pellets. The fracturing fluid may also include athermal stabilizer, for example sodium thiosulfate, methanol, ethyleneglycol, isopropanol, thiourea, and/or sodium thiosulfite. The fracturingfluid may also include KCl as a clay stabilizer.

B. Acidizing

Producing oil and gas wells have long been treated to stimulateproduction thereof utilizing a method termed “acidizing” in which anemulsion of an aqueous mineral acid either alone or in combination withvarious surfactants, corrosion inhibiting agents, and hydrocarbon oilsis added to a producer well. Presumably, such treatments tend to removedeposits from the area of the subterranean oil or gas formationimmediately adjacent to the production well bore, thus increasing thepermeability of the formation and allowing residual oil or gas to berecovered through the well bore. Another object of such “acidizing”treatment of oil or gas producer wells is the removal of water from theinterstices of the formation by the use of a composition whichmaterially lowers the interfacial forces between the water and the oilor gas. Various surface-active agents have been recommended for thisuse.

Producing oil and gas wells have long been treated to stimulateproduction thereof utilizing a method termed “acidizing” in which anemulsion of an aqueous mineral acid either alone or in combination withvarious surfactants, corrosion inhibiting agents, and hydrocarbon oilsis added to a producer well. Presumably, such treatments tend to removedeposits from the area of the subterranean oil or gas formationimmediately adjacent to the production well bore, thus increasing thepermeability of the formation and allowing residual oil or gas to berecovered through the well bore. Another object of such “acidizing”treatment of oil or gas producer wells is the removal of water from theinterstices of the formation by the use of a composition whichmaterially lowers the interfacial forces between the water and the oilor gas. Various surface-active agents have been recommended for thisuse.

Acidizing, and fracturing procedures using acidic treatment fluids, arecommonly carried out in subterranean well formations to accomplish anumber of purposes including, but not limited to, to facilitate therecovery of desirable hydrocarbons from the formation. As used herein,the term “treatment fluid” refers to any fluid that may be used in asubterranean application in conjunction with a desired function and/orfor a desired purpose. The term “treatment fluid” does not imply anyparticular action by the fluid or any component thereof.

One commonly used aqueous acidic treatment fluid comprises hydrochloricacid. Other commonly used acids for acidic treatment fluids includehydrofluoric acid, acetic acid, formic acid, citric acid, ethylenediamine tetra acetic acid (“EDTA”), glycolic acid, sulfamic acid, andderivatives or combinations thereof.

Acidic treatment fluids are used in various subterranean operations. Forexample, formation acidizing or “acidizing” is a method for, among otherpurposes, increasing the flow of desirable hydrocarbons from asubterranean formation. In a matrix acidizing procedure, an aqueousacidic treatment fluid is introduced into a subterranean formation via awell bore therein under pressure so that the acidic treatment fluidflows into the pore spaces of the formation and reacts with (e.g.,dissolves) the acid-soluble materials therein. As a result, the porespaces of that portion of the formation are enlarged, and thepermeability of the formation may increase. The flow of hydrocarbonsfrom the formation therefore may be increased because of the increase information conductivity caused, inter alia, by dissolution of theformation material. In fracture acidizing procedures, one or morefractures are produced in the formation(s) and an acidic treatment fluidis introduced into the fracture(s) to etch flow channels therein. Acidictreatment fluids also may be used to clean out well bores to facilitatethe flow of desirable hydrocarbons. Other acidic treatment fluids may beused in diversion processes and well bore clean-out processes. Aspecific example is filter cake removal.

To increase the viscosity of an aqueous acidic treatment fluid, asuitable gelling agent may be included in the treatment fluid (oftenreferred to as “gelling” the fluid). Gelling an aqueous acidic treatmentfluid may be useful, among other purposes, to prevent the acid frombecoming prematurely spent and inactive. Additionally, gelling anaqueous acidic treatment fluid may enable the development of widerfractures so that the gelled acidic treatment fluid may delay theinteraction of the acid with an acid soluble component in the well boreor the formation. Moreover, gelling an aqueous acidic treatment fluidmay permit better fluid loss control.

Acidic treatment fluids used in subterranean operations arepredominantly water-based fluids that comprise gelling agents toincrease their viscosities. Common gelling agents includepolysaccharides (such as xanthan), synthetic polymers (such aspolyacrylamide), and surfactant gel systems. To assist the gellingagents in maintaining these viscosities in the presence of the hightemperatures and slat concentrations experienced downhole thecomposition includes the polymer combinations of the present invention.

The aqueous base fluids of the acidic treatment fluids of the presentinvention generally comprise fresh water, salt water, sea water, a brine(e.g., a saturated salt water or formation brine), or a combinationthereof. Other water sources may be used, including those comprisingmonovalent, divalent, or trivalent cations (e.g., magnesium, calcium,zinc, or iron) and, where used, may be of any weight. If a water sourceis used that contains such divalent or trivalent cations inconcentrations sufficiently high to be problematic, then such divalentor trivalent salts may be removed, either by a process such as reverseosmosis, or by raising the pH of the water to precipitate out suchdivalent salts to lower the concentration of such salts in the waterbefore the water is used. Another method would be to include a chelatingagent to chemically bind the problematic ions to prevent theirundesirable interactions with the clarified xanthan. Suitable chelantsinclude, but are not limited to, citric acid or sodium citrate, ethylenediamine tetra acetic acid (“EDTA”), hydroxyethyl ethylenediaminetriacetic acid (“HEDTA”), dicarboxymethyl glutamic acid tetrasodium salt(“GLDA”), diethylenetriaminepentaacetic acid (“DTPA”),propylenediaminetetraacetic acid (“PDTA”),ethylenediaminedi(o-hydroxyphenylacetic) acid (“EDDHA”), glucoheptonicacid, gluconic acid, and the like, and nitrilotriacetic acid (“NTA”).Other chelating agents also may be suitable. One skilled in the art willreadily recognize that an aqueous base fluid containing a high level ofmulti-valent ions should be tested for compatibility prior to use.

The gelling agents comprising the polymers of the present invention maybe present in an acidic treatment fluid of the present invention in anamount of from about 1 lb/Mgal to about 200 lb/Mgal. In embodimentswherein the gelling agents comprising clarified xanthan further comprisescleroglucan, one may include about 1 lb/Mgal to about 200 lb/Mgal ofscleroglucan. In an acidic treatment fluid that comprises hydrochloricacid, one may include about 1 to about 200 lb/Mgal of scleroglucan. Inembodiments wherein the gelling agents comprising clarified xanthanfurther comprise diutan, one may include about 1 to about 200 lb/Mgal ofdiutan. In an acidic treatment fluid that comprises about 15%hydrochloric acid, one may include about 1 to about 200 lb/Mgal ofdiutan. In some embodiments, one may include about 10 to about 150lb/Mgal of clarified xanthan, scleroglucan, and/or diutan. A person ofskill in the art with the benefit of this disclosure will recognize thatany specific concentration or narrower range of concentrations of thegelling agents of the present invention encompassed by the broaderconcentration ranges specifically articulated above may be used and/ormay be particularly advantageous for a particular embodiment of thepresent invention.

In certain embodiments, the acidic treatment fluids of the presentinvention also may comprise any additional additive that may be suitablein a particular application of the present invention, including, but notlimited to, any of the following: hydrate inhibitors, clay stabilizers,bactericides, salt substitutes (such as tetramethyl ammonium chloride),relative permeability modifiers (such as HPT-1™. chemical additiveavailable from Halliburton Energy Services, Duncan, Okla.), sulfidescavengers, fibers, nanoparticles, consolidating agents (such as resinsand/or tackifiers), corrosion inhibitors, corrosion inhibitorintensifiers, pH control additives, surfactants, breakers, fluid losscontrol additives, scale inhibitors, asphaltene inhibitors, paraffininhibitors, salts, bactericides, crosslinkers, stabilizers, chelants,foamers, defoamers, emulsifiers, demulsifiers, iron control agents,solvents, mutual solvents, particulate diverters, gas phase, carbondioxide, nitrogen, other biopolymers, synthetic polymers, frictionreducers, combinations thereof, or the like. The acidic treatment fluidsof the present invention also may include other additives that may besuitable for a given application, as will be recognized by a person ofordinary skill in the art, with the benefit of this disclosure.

While typically not required, the acidic treatment fluids of the presentinvention also may comprise breakers capable of reducing the viscosityof the acidic treatment fluid at a desired time. Examples of suchbreakers that may be suitable for the acidic treatment fluids of thepresent invention include, but are not limited to, sodium chlorite,hypochlorites, perborates, persulfates, peroxides (including organicperoxides), enzymes, derivatives thereof, and combinations thereof.Other suitable breakers may include suitable acids. Examples ofperoxides that may be suitable include tert-butyl hydroperoxide andtert-amyl hydroperoxide. A breaker may be included in an acidictreatment fluid of the present invention in an amount and formsufficient to achieve the desired viscosity reduction at a desired time.The breaker may be formulated to provide a delayed break, if desired.For example, a suitable breaker may be encapsulated if desired. Suitableencapsulation methods are known to those skilled in the art. Onesuitable encapsulation method that may be used involves coating thebreaker(s) with a material that will degrade when placed downhole so asto release the breaker at the appropriate time. Coating materials thatmay be suitable include, but are not limited to, polymeric materialsthat will degrade when downhole. The terms “degrade,” “degradation,” or“degradable” refer to both the two relatively extreme cases ofhydrolytic degradation that the degradable material may undergo, i.e.,heterogeneous (or bulk erosion) and homogeneous (or surface erosion),and any stage of degradation in between these two. This degradation canbe a result of, inter alia, a chemical or thermal reaction or a reactioninduced by radiation. Suitable examples of materials that can undergosuch degradation include polysaccharides such as dextran or cellulose;chitins; chitosans; proteins; aliphatic polyesters; poly(lactides);poly(glycolides); poly(.epsilon.-caprolactones); poly(hydroxybutyrates);poly(anhydrides); aliphatic polycarbonates; orthoesters,poly(orthoesters); poly(amino acids); poly(ethylene oxides);polyphosphazenes; derivatives thereof; and combinations thereof. Ifused, a breaker should be included in a composition of the presentinvention in an amount sufficient to facilitate the desired reduction inviscosity in a viscosified treatment fluid. For instance, peroxideconcentrations that may be used vary from about 0.1 to about 10 gallonsof peroxide per 1000 gallons of the acidic treatment fluid.

C. Enhanced Oil Recovery

The present invention may be employed with other techniques to furtherimprove hydrocarbon recovery from subterranean formations. Initially,oil is produced from the fractured formation by pressure depletion(primary recovery). In this method, the differential pressure betweenthe formation and a production well or wells forces the oil containedwithin the formation toward a production well where it can be recovered.Traditionally secondary recovery processes through injection of water orgas are used to displace additional oil toward producing wells.Typically, up to about 35 percent of the oil which is initiallycontained in a formation can be recovered in average through primary andsecondary recovery. This leaves a large quantity of oil within theformation. Additionally, some formations contain oil which is tooviscous to be efficiently recovered from the formation using primary andsecondary processes. Because of the need to recover a larger percentageof the oil from a formation, methods have been developed to recover oilwhich could not be recovered using only pressure depletion techniques.These methods are typically referred to as “enhanced oil recoverytechniques” (EOR).

Thus, the present invention is also directed to a method for recoveringcrude oil from a subterranean formation, comprising introducing to theformation an aqueous medium comprising water or brine and thecomposition of the present invention including a combination of anionicpolymer and cationic polymer described above.

The global average recovery factor for conventional oil fields is about35% and it could be raised up to 50% through enhanced oil recovery.There are two essentials components to EOR: improving displacementefficiency and improving macroscopic sweep efficiency. The presentinvention enhances oil recovery by maintaining stable viscosity at hightemperatures. The method of the invention is particularly useful in thestimulation of oil and gas wells which have failed to respond toacidizing treatment of the producing well including the use of variousacids with various surfactants.

1. Chemical Flooding

A promising EOR method is an enhanced oil recovery process referred toas chemical flooding which generally covers the use of polymer and/orsurfactant slugs. In polymer flooding, a polymer solution is injected todisplace oil toward producing wells. The polymer solution is designed todevelop a favorable mobility ratio between the injected polymer solutionand the oil/water bank being displaced ahead of the polymer. However,the use of polymer is not always satisfactory as many polymer solutionsare sensitive to brine type and concentration which can affect theapparent viscosity of the solution. In surfactant flooding, an aqueoussolution containing surfactant is injected into the oil rich formation.Residual oil drops are deformed as a result of low Interfacial Tensionprovided by surfactant solution and drops are displaced through the porethroats and displaced oil is the recovered. See U.S. Pat. No. 7,789,160to Hough et al. incorporated herein by reference in its entirety.

The present compositions advantageously are compatible with anionicsurfactants typically used to decrease interfacial tension to alsoassist in enhancing oil recovery from subterranean formations.

The present invention proves enhanced oil recovery. For example, thepresent invention is also directed to a method for recovering crude oilfrom a subterranean formation, comprising introducing to the formationan aqueous medium comprising water or brine and the composition of thepresent invention including a combination of polyanionic polymer andpolycationic polymer described above.

There are two important components to EOR: improving displacementefficiency and improving macroscopic sweep efficiency. The presentinvention enhances oil recovery by maintaining stable viscosity at hightemperatures. The method of the invention is particularly useful in thestimulation of oil and gas wells which have failed to respond toacidizing treatment of the producing well including the use of variousacids with various surfactants.

The present compositions advantageously are compatible with anionicsurfactants typically used to decrease interfacial tension to alsoassist in enhancing oil recovery from subterranean formations.

The aqueous medium of the composition may be soft water, brackish wateror brine. Typically the aqueous medium in compositions used to treatsubterranean formations comprises brine.

2. Other Ingredients

Compositions of the invention may contain components in addition towater, the first cationic or cationaizable polymer, the second anionicor anionizable polymer and optional surfactants. Such additionalcomponents are, for example, co-solvents, acids, bases, buffers,chelating agents for the control of multivalent cations, freezing pointdepressants, etc.

For example, a hydrocarbon recovery composition according to the presentinvention may be provided to the hydrocarbon containing formation aloneor with other compounds for enhancing oil recovery. For example, theseother compounds may be other nonionic additives (e.g., alcohols,ethoxylated alcohols and/or sugar based esters). Some embodiments haveless than 0.3 weight percent of one or more anionic surfactants (e.g.sulfates, sulfonates, ethoxylated sulfates, and/or phosphates). In someembodiments the composition has less than 0.3 wt % each of anionicsurfactant, amphoteric surfactant and zwitterionic surfactant. Ifdesired, there may be an absence of anionic surfactant, an absence ofamphoteric surfactant, and an absence of zwitterionic surfactant.

a. Alcohol

Alcohol can be used as mutual solvent to reduce water saturation. Theinterfacial tension between oil and ethanol is much lower than betweenoil and brine.

Capillary forces of retention for the alcohol are much reduced comparedto those for brine.

It has been reported that isopropyl or butyl alcohol plus methyl alcoholcould be used in miscible displacement to increase oil recovery ofnaphtha and mineral oil.

Others have investigated enhanced oil recovery by alcohol flooding.Their process design was strongly guided by the ternary phase ofalcohol/oil/brine. They showed that oil recovery was highly dependent onthe choice of alcohol/oil/brine combinations. Others have reported thatinjection of appropriate combinations of oil-soluble and water-solublesolvents such as alcohols and ketones could significantly enhance oilrecovery.

In an embodiment, an aliphatic nonionic additive may be used in ahydrocarbon recovery composition. As used herein, the term “aliphatic”refers to a straight or branched chain of carbon and hydrogen atoms. Insome embodiments, an aliphatic portion of an aliphatic nonionic additivemay have an average carbon number from 10 to 24. In some embodiments, analiphatic portion of an aliphatic nonionic additive may have an averagecarbon number from 12 to 18. In some embodiments, the aliphatic nonionicadditive may include a branched aliphatic portion. A branched aliphaticportion of an aliphatic nonionic additive may have an average carbonnumber from 16 to 17. In some embodiments, a branched aliphatic group ofan aliphatic nonionic additive may have less than about 0.5 percentaliphatic quaternary carbon atoms. In an embodiment, an average numberof branches per aliphatic nonionic additive ranges from about 0.1 toabout 2.5. In other embodiments, an average number of branches peraliphatic nonionic additive ranges from about 0.7 to about 2.5.

Methyl branches may represent between about 20 percent to about 99percent of the total number of branches present in the branched nonionicadditive. In some embodiments, methyl branches may represent greaterthan about 50 percent of the total number of branches in a branchednonionic additive. The number of ethyl branches in the alcohol mayrepresent, in certain embodiments, less than about 30 percent of thetotal number of branches. In other embodiments, the number of ethylbranches, if present, may be between about 0.1 percent and about 2percent of the total number of branches. Branches other than methyl orethyl, if present, may be less than about 10 percent of the total numberof branches. In some embodiments, less than about 0.5 percent of thetotal number of branches are neither ethyl nor methyl groups.

In an embodiment, an aliphatic nonionic additive may be a long chainaliphatic alcohol. The term “long chain,” as used herein, refers to acarbon chain having an average carbon number from 10 to 30. A long chainaliphatic alcohol (e.g., a long chain primary alcohol) may be purchasedcommercially (e.g., NEODOL alcohols manufactured by Shell Chemical Co.,Houston, Tex.). In certain embodiments, a long chain aliphatic alcoholmay be prepared by a variety of generally known methods. A long chainaliphatic alcohol may have an average carbon number from 10 to 24. Insome embodiments, a long chain aliphatic alcohol may have an averagecarbon number from 12 to 18. In other embodiments, a long chainaliphatic alcohol may have an average carbon number from 16 to 17.

In an embodiment, a portion of the long chain aliphatic alcohol may bebranched. Branched long chain aliphatic alcohols may be prepared byhydroformylation of a branched olefin. Preparations of branched olefinsare described in U.S. Pat. No. 5,510,306 to Murray, entitled “Processfor Isomerizing Linear Olefins to Isoolefins;” U.S. Pat. No. 5,648,584to Murray, entitled “Process For Isomerizing Linear Olefins toIsoolefins” and U.S. Pat. No. 5,648,585 to Murray, entitled “Process ForIsomerizing Linear Olefins to Isoolefins,” all of which are incorporatedby reference herein. Preparations of branched long chain aliphaticalcohols are described in U.S. Pat. No. 5,849,960 to Singleton et al.,entitled “Highly Branched Primary Alcohol Compositions, andBiodegradable Detergents Made Therefrom;” U.S. Pat. No. 6,150,222 toSingleton et al., entitled “Highly Branched Primary AlcoholCompositions, and Biodegradable Detergents Made Therefrom;” U.S. Pat.No. 6,222,077 to Singleton et al., entitled “Highly Branched PrimaryAlcohol Compositions, and Biodegradable Detergents Made Therefrom,” allof which are incorporated by reference herein.

In some embodiments, branches of a branched aliphatic group of a longchain aliphatic alcohol may have less than about 0.5 percent aliphaticquaternary carbon atoms. In an embodiment, an average number of branchesper long chain aliphatic alcohol ranges from about 0.1 to about 2.5. Inother embodiments, an average number of branches per alcohol ranges fromabout 0.7 to about 2.5.

Methyl branches may represent between about 20 percent to about 99percent of the total number of branches present in the branched longchain aliphatic alcohol. In some embodiments, methyl branches mayrepresent greater than about 50 percent of the total number of branchesin a branched long chain aliphatic alcohol. The number of ethyl branchesin the alcohol may represent, in certain embodiments, less than about 30percent of the total number of branches. In other embodiments, thenumber of ethyl branches, if present, may be between about 0.1 percentand about 2 percent of the total number of branches. Branches other thanmethyl or ethyl, if present, may be less than about 10 percent of thetotal number of branches. In some embodiments, less than about 0.5percent of the total number of branches are neither ethyl nor methylgroups.

b. Aliphatic Anionic Surfactants

In an embodiment, an aliphatic anionic surfactant may be used in ahydrocarbon recovery composition. In certain embodiments, an aliphaticportion of an aliphatic anionic surfactant may have an average carbonnumber from 10 to 24. In some embodiments, an aliphatic portion of analiphatic anionic surfactant may have an average carbon number from 12to 18. In other embodiments, an aliphatic portion of an aliphaticanionic surfactant may have an average carbon number from 16 to 17. Insome embodiments, the aliphatic anionic surfactant may include abranched aliphatic portion. In some embodiments, a branched aliphaticgroup of an aliphatic anionic surfactant may have less than about 0.5percent aliphatic quaternary carbon atoms. In an embodiment, an averagenumber of branches per aliphatic anionic surfactant ranges from about0.1 to about 2.5. In other embodiments, an average number of branchesper aliphatic anionic surfactant ranges from about 0.7 to about 2.5.

Methyl branches may represent between about 20 percent to about 99percent of the total number of branches present in the branched anionicsurfactant. In some embodiments, methyl branches may represent greaterthan about 50 percent of the total number of branches in a branchedanionic surfactant. The number of ethyl branches in the alcohol mayrepresent, in certain embodiments, less than about 30 percent of thetotal number of branches. In other embodiments, the number of ethylbranches, if present, may be between about 0.1 percent and about 2percent of the total number of branches. Branches other than methyl orethyl, if present, may be less than about 10 percent of the total numberof branches. In some embodiments, less than about 0.5 percent of thetotal number of branches are neither ethyl nor methyl groups.

In an embodiment which further employs aliphatic anionic surfactant, asolution may be provided which contains an effective amount of analiphatic anionic surfactant selected from the group of compounds havingthe general formula: R₁O(C₃H₆O)_(m)(C₂H₄O)_(n)YX wherein R₁ is a linearor branched alkyl radical, an alkenyl radical, or an alkyl or alkenylsubstituted benzene radical, the non-aromatic portion of the radicalcontaining from 6 to 24 carbon atoms; m has an average value of from 1to 10; n has an average value of from 1 to 10; Y is a hydrophilic group;and X is a cation, preferably monovalent, for example N, K, NH₄ ⁺. Y isa suitable hydrophilic group or substituted hydrophilic group such as,for example, the sulfate, sulfonate, phosphonate, phosphate orcarboxylate radical. Preferably, R₁ is a branched alkyl radical havingat least two branching groups and Y is a sulfonate or phosphate group.

3. Other Optional Additives for Enhanced Oil Recovery

The aqueous fluid of the present invention may, optionally, furthercomprise clay stabilization or sand stabilization material. During oilrecovery processes, sands and other materials may become entrained inthe recovered oil. This may be mitigated by the addition of a claystabilization or sand stabilization material. Suitable claystabilization or sand stabilization materials include epoxy resins,polyfunctional cationic polymers, such aspoly(N-acrylamidomethyltrimethyl ammonium chloride) orpoly(vinylbenzyltrimethyl ammonium chloride).

Other optional ingredients that may be added to the aqueous fluid of thepresent invention include, but are not limited to polymers such asbiopolysaccharides, cellulose ethers, acrylamide-derived polymers,corrosion inhibitors, oxygen scavengers, bactericides, and so forth, andany combination thereof.

The aqueous fluid of the present invention is introduced into the crudeoil-bearing formation, typically by injecting the fluid into theformation.

In the case of a carbonate formation having hydrophobic surfaces,addition of the organophosphorous material to the aqueous flooding fluidmodifies such surfaces to increase the surface energy of such surfacesand render such surfaces more readily wettable by water. The surfacemodified formation more readily imbibes the aqueous flooding fluid, thusincreasing the amount of aqueous fluid imbibed by the formation andincreasing the amount of crude oil displaced from the formation by theaqueous fluid.

The aqueous fluid may be used in secondary or tertiary oil recoveryprocesses, although the use of such fluids in other applications is alsonot excluded.

4. Methods of Use for Enhanced Oil Recovery

The aqueous medium utilized to form the solution including theorganophosphorous material of the invention can be soft water, brackishwater, or a brine. The aqueous fluid of the present invention isintroduced into the crude oil-bearing formation, typically by injectingthe fluid into the formation.

Optionally, after injection of the aqueous fluid comprising the presentphosphate esters of the present invention addition to crude oil havinggenerally the viscosity of the oil-bearing formation of the oil well tobe treated, various hydrocarbon solvents may be employed to displace theaqueous solution out into the reservoir. Such hydrocarbon solvents asthe low molecular weight, generally liquid hydrocarbons boiling belowthe gasoline range, such as the lower alkanes including butane, propane,pentane, hexane and heptane, as well as natural gasoline, petroleumnaphtha and kerosene or mixtures of these hydrocarbons, are useful. Bothsweet and sour crude oil is useful as a hydrocarbon to displace theaqueous solution out into the subterranean reservoir of oil or gas.

Optionally, injection of a preflush fluid may be utilized prior toinjection of the aqueous fluid of the present invention. The preflushmay consist of a hydrocarbon fluid, a brine solution, or simply water.

Also, injection of the aqueous fluid comprising the present phosphateesters may optionally be followed by an injection of a surfactant, amobility control fluid or a polymeric flush, which is typically apolymer-thickened aqueous solution, using, for example the polymersdisclosed above, into the formation to further enhance oil recovery. Thepolymeric solution is utilized to drive or push the now oil bearingsurfactant flood out of the reservoir, thereby “sweeping” crude oil outof the reservoir. Further, the polymeric solution has a very highviscosity which helps to prevent what is referred to in the industry aschanneling or “fingering”, thus improving sweep efficiency.

This polymeric flush or mobility control fluid may once again befollowed by a water flush which may be brine or saline or softenedwater, or fresh water.

Oil is recovered at a production well to be spaced apart from theinjection well as the drive fluid pushes the mobility buffer slug whichsweeps the oil out of the pores in the formation and to the productionwell. Once the water/oil emulsion reaches the surface, it is put intoholding tanks where it is subsequently demulsified, thereby allowing theoil to separate from the water through the natural forces of gravity.

For example, a hydrocarbon recovery composition including the phosphateesters of the present invention may be added to a portion of hydrocarboncontaining formation that may have an average temperature of less than80° C. To facilitate delivery of an amount of the hydrocarbon recoverycomposition to the hydrocarbon containing formation, the hydrocarboncomposition may be combined with water or brine to produce an injectablefluid. Typically about 0.01 to about 5 wt % of the phosphate ester,based on the total weight of injectable fluid, may be injected into thehydrocarbon containing formation through an injection well. In certainembodiments, the concentration of the hydrocarbon recovery compositioninjected through the injection well may be about 0.05% to about 3 wt. %,based on the total weight of injectable fluid. In some embodiments, theconcentration of the hydrocarbon recovery composition may be about 0.1%to about 1 wt. % based on the total weight of injectable fluid.

In some embodiments, a hydrocarbon recovery composition may be added toa portion of a hydrocarbon containing formation.

XI. Home Care or Industrial Care Compositions

In one embodiment, the present invention is directed to a home care orindustrial cleaning composition, such as a liquid detergent, a laundrydetergent, a hard surface cleanser, a dish wash liquid, or a toilet bowlcleaner, comprising water, one or more surfactants, and a polymer of thepresent invention. Suitable surfactants include those described above inregard to the personal care composition embodiments of the presentinvention. Such cleaning compositions may optionally further compriseone or more of water miscible organic solvents, such as alcohols andglycols, and/or one or more additives.

Suitable additives are known in the art and include, for example,organic builders, such as organophosphonates, inorganic builders, suchas ammonium polyphosphates, alkali metal pyrophosphates, zeolites,silicates, alkali metal borates, and alkali metal carbonates, bleachingagents, such as perborates, percarbonates, and hypochlorates,sequestering agents and anti-scale agents, such as citric acid andethylenediaminetetraacetic acid, inorganic acids, such as phosphoricacid and hydrochloric acid, organic acids, such as acetic acid,abrasives, such as silica or calcium carbonate, antibacterial agents ordisinfectants, such as triclosan and cationic biocides, for example(N-alkyl)benzyldimethylammonium chlorides, fungicides, enzymes,opacifing agents, pH modifiers, dyes, fragrances, and preservatives.

In an embodiment the home care or industrial cleaner benefit agent isselected from the group consisting of soil release agents, fabricsoftener, surfactants, builders, binders, bleach and fragrances.

In an embodiment the home care or industrial cleaning composition forcleaning fabrics or hard surfaces comprising, the composition of thepresent invention and a surfactant and a home care or industrial cleanerbenefit agent.

In an embodiment the composition is a detergent composition andcomprises: the polymer, at least one detersive surfactant, and abuilder.

The invention also encompasses a method for cleaning a substrateselected from the group consisting of a hard surface and a fabric,comprising applying the composition of the present invention to thesubstrate.

Examples of the prevent invention are set forth below. Unless otherwiseindicated, all parts, percentages, and proportions herein are by weight.

EXAMPLES Example 1 Preparation of HASE Thickener Systems

The HASE polymers are each made according to the procedure set forthbelow.

In one embodiment, the emulsion polymerization technique comprisescharging a kettle or reactor, and then heating the kettle or reactorwhile purging with nitrogen. The nitrogen purge is maintained throughoutthe run. A monomer emulsion (ME) of DI water (deionized water),surfactant, methyl acrylic acid, ethyl acrylate, and hydrophobicassociative monomer is added to the kettle, as well as an initiatorsolution (IS) of DI water and ammonium persulfate. The kettle is heldfor over approximately 3 hours at constant elevated temperature, atabout 80° C., and the remainder of monomer emulsion and initiatorsolution is added. The kettle is held for an additional 30 minutes whilerinsing the additional funnel of IS and its tubing (disconnected fromthe batch) with water. (The tubing is then reconnected to the batch.)Part 1 of a chaser system/solution of tertbutyl peroxybenzoate is addedto the kettle and IS additional funnel is filled with Part 2 of thechaser system/solution of isoascorbic acid and DI water. Part 2 is addedover the course of 30 minutes. The kettle is held at constant elevatedtemperature for 30 minutes. The initiator and chaser solutions areprovided to convert left over monomers to oligomerize them to reduceVOCs. If desired to avoid the initiator and chaser solutions excessmonomer could be removed by stripping.

The surfactant of Example 1 included RHODAPEX AB20 which is a surfactantcontaining ammonium salt of sulphated alcohol ethoxylate available fromRhodia Inc. The initiator of Example 1 included ammonium persulfate.

The hydrophobic associative monomer of Example 1 is an alkyl alkoxylateaccording to structure (VI):

wherein R6 is methyl, N is in the range from 8 to 10 and M is in therange from 18 to 22. The alkoxylate is made as follows: methanol isalkoxylated with moles propylene oxide and moles ethylene oxide chargedto a glass flask equipped with a PTFE blade agitator, temperaturesensor, dry compressed air purge line and a water cooled condenser. Theliquid ethoxylate is warmed, stirred, and MEHQ is added. A purge of dryair is passed through the liquid and later methacrylic anhydride isadded. The temperature is stabilized and held between 70-74° C. for fiveand a half hours, and then the liquid is cooled. Methacrylic acid andwater are added and the liquid product is discharged.

Example 2 Formulation Preparation for Testing Thickening Efficiency (KU)

Formulation preparation combined 108 grams Binder (RHOPLEX SG30)+61grams deionized water+HASE thickener of Example 1. RHOPLEX SG30 is a100% acrylic emulsion available from Dow Coating Materials and is thebinder latex.

The KU formulation described above was used to evaluate viscosityprofiles and obtain the results reported on TABLES 1 and 2. The KUviscosity of the HASE thickener polymer with RHOPLEX SG30 was measuredbefore and after addition of IGEPAL CO887 surfactant. IGEPAL CO-887 is asurfactant containing Nonylphenol ethoxylate available from Rhodia Inc.

FIGS. 1-6 show data from measuring the above-described formulationeither before or after addition of surfactant.

Viscosity profiles were run as follows: At 25° C. using couette whichconsists of a bob and cup, one is moving relative to the other.

FIG. 1 shows Viscosity Profiles of formulations prepared with HASEthickeners containing a (meth)acrylate-[EO]x-[PO]y-CH3 hydrophobicassociative monomer (in RHOPLEX SG30) without surfactant.

FIG. 2 shows Viscosity Profiles of formulations prepared with HASEthickeners containing a (meth)acrylate-[EO]x-[PO]y-CH3 hydrophobicassociative monomer (in RHOPLEX SG30) before and after surfactantaddition (IGEPAL CO887, 1 g).

FIG. 3 shows Viscosity Profiles of formulations prepared with HASEthickeners containing a (meth)acrylate-[EO]x-[PO]y-CH3 hydrophobicassociative monomer (in RHOPLEX SG30) before and after surfactantaddition (IGEPAL CO887, 2 g).

FIG. 4 shows Viscosity Profiles of formulations prepared with HASEthickeners containing a (meth)acrylate-[EO]x-[PO]y-CH3 hydrophobicassociative monomer (in RHOPLEX SG30) before and after surfactantaddition (IGEPAL CO887, 3 g).

FIG. 5 shows Yield Stress Profiles of formulations prepared with HASEthickeners containing a (meth)acrylate-[EO]x-[PO]y-CH3 hydrophobicassociative monomer (in RHOPLEX SG30) without surfactant.

FIG. 6 shows Yield Stress Profiles of formulations prepared with HASEthickeners containing a (meth)acrylate-[EO]x-[PO]y-CH3 hydrophobicassociative monomer (in RHOPLEX SG30) before and after surfactantaddition (IGEPAL CO887, 2 g).

TABLES 1 and 2 show KU Viscosity of HASE polymers in RHOPLEX SG30 beforeand after addition of IGEPAL CO887 surfactant.

TABLE 1 Thickening Efficiency in RHOPLEX SG30 After 1 gram of IGEPALCO887 surfactant Before After Decrease Sample surfactant surfactant (%)Number KU ICI KU ICI KU 1 94.8 0.68 95.4 0.65 0.00

TABLE 2 thickening efficiency in RHOPLEX SG30 After 2 grams of IGEPALCO887 surfactant Decrease Sample Before surfactant After surfactant (%)Number KU ICI KU ICI KU 1 94.8 0.68 95.1 0.65 0.00

The data shows synthesis of HASE thickeners of the present inventionshow good resistance to viscosity loss after addition of surfactant.

Example 3 Sample Preparation for Formulations with Stain

Table 3 shows representative examples (Sample Number 4 and Sample Number5) having viscosity values (KU, ICI and Zhan cup) of a stain (asdescribed below) after addition of a representative polymer as claimedherein, which incorporates the specialized hydrophobic associativemonomer. A stain viscosity is also showed as reference (Sample Number3).

TABLE 3 Experiments carried out using polymer of the present inventionincorporating the specialized hydrophobic associative monomer. ZhanSample Stain Polymer Polymer ICI Cup Time¹ Number (g) ID (g) KU (P)(sec) (h) 3 150 — — 48.2 0.15 17.0 5 4 150 A 2.0 51.5 0.15 21.0 168 5150 B 2.0 51.8 0.25 23.0 168 ¹Stability at room temperature

Sample Number 3 is a commercially available wood stain, which has a lowviscosity. The stain without polymer (Sample Number 3) showed separationof pigments/fine particles from solution within 5 hours. The stains withpolymer synthesized with the specialized associative monomer (SampleNumber 4 and Sample Number 5) appeared to show a homogenous mixture andno separation to the naked eye during 168 hours. Moreover KU viscositywas not increased considerably.

Formulations with Stain-Formulation with stain (28.35% solids) wascarried out in a glass container according to the followingrepresentative procedure: to a solution of stain (150 g) at pH of 8.73was added slowly the polymer (incorporating the specialized hydrophobicassociative monomer). After being stirred in a roller mixer during 12hours, the mixture was allowed to stand at least 5 minutes.Subsequently, KU, ICI, Zhan cup and pH values were determined; procedurewas repeated until phase separation was not observed. Stain used forthese formulations is a commercially available stain cedar tone.

Krebs stormer viscosimeter for KU viscosity: Testing using the KrebsStormer determines the load required to rotate an offset paddle immersedin the sample at 200 rpm. The Krebs Stormer is normally used forconsistency measurement on paints and coating compositions. Results arereported in Krebs Units and the nature of the measurement does not allowconversion from Krebs units to any other more common viscosity unit suchas centipoise. Test is done at or near room temperature. The design ofthe viscometer is based on the Standards ASTM D 562-81 and GB/T 9269-88.

A Zahn cup is a viscosity measurement device used in the paint industry.It is commonly a stainless steel cup with an orifice in the center ofthe bottom of the cup. The viscosity of a liquid, when measured by theZahn viscosimeter, is expressed in Zahn seconds; that is, the timerequired for a definite volume of liquid to flow through the orifice inthe bottom of a metal cup.

The ICI cone and plate viscometer is a relatively high shear rateinstrument capable of absolute viscosity measurement. The use of theinstrument has been the measurement of viscosity for prediction ofbrushability (ASTM method D4287). The device has a small diameter wideangle cone rotated at a constant speed, in contact with a plate. Theviscosity is measured through a calibrated spring torque device.

It should be apparent that embodiments other than those expresslydescribed above come within the spirit and scope of the presentinvention. Thus, the present invention is not defined by the abovedescription but by the claims appended hereto.

That which is claimed:
 1. A polymer which is an anti-settling additive,the polymer comprising (a) about 25 to about 70 weight percent based ontotal monomers of at least one carboxylic acid monomer selected from thegroup consisting of methacrylic acid, acrylic acid, and a combinationthereof; (b) about 30 to about 70 weight percent based on total monomersof at least one copolymerizable non-ionic C₂-C₁₂ alphabeta-ethylenically unsaturated monomer of the structure (III):CH₂═CYZ  (III) wherein Y is H; Z is —COOR′, wherein R′ is alkyl suchthat the at least one copolymerizable non-ionic C₂-C₁₂ alphabeta-ethylenically unsaturated monomer comprises ethyl acrylate; (c)about 0.05 to about 20 weight percent based on total monomer weight ofat least one specialized associative monomer wherein the specializedassociative monomer is an alkyl alkoxylate according to structure (VI):

wherein R₃ is CH₃, R₄ is CH₃, R₅ is CH₃, N is from 8 to 10, and M isfrom 18 to
 22. 2. The polymer of claim 1, wherein the polymer is ananti-settling additive having a weight average molecular weight of 1,000to 1,200,000 g/mol.
 3. The polymer of claim 1, wherein the polymer is ahydrophobically modified alkali swellable emulsion thickener pHresponsive polymer having a molecular weight of 750,000 to 5,000,000g/mol.
 4. A coating composition comprising the polymer of claim 1,wherein the coating composition has a viscosity of less than about 200KU.
 5. A coating composition comprising the polymer of claim 1, whereinthe polymer has a weight average molecular weight of less than about250,000 g/mole and the coating composition has a viscosity of less thanabout 100 KU.
 6. The polymer of claim 1, wherein the polymer is a pHresponsive copolymer, comprising based on total weight of monomers: A.about 25-40 weight percent of said at least one carboxylic acid monomer;B. about 30-50 weight percent of said at least one non-ionic,copolymerizable C2-C12 alpha, beta-ethylenically unsaturated monomer;and C. about 5 to 20 weight percent of said at least one specializednonionic ethylenically unsaturated specialized hydrophobic associativemonomer.
 7. The polymer of claim 1, wherein the at least one carboxylicacid monomer (a) is present from about 25 weight percent to about 40weight percent based on total monomer weight.
 8. An aqueous compositioncomprising water and the polymer of claim 1, wherein the polymer is a pHresponsive polymer.
 9. The aqueous composition of claim 8, furthercomprising an emulsifier, wherein the aqueous composition is a pHresponsive composition.
 10. The aqueous composition of claim 8,containing particles having an average particle size of about 500 toabout 3000 angstroms and wherein the aqueous composition has aBrookfield viscosity of about 100 to about 500,000 cps as a 1 percentsolution in ammonium salt at pH 9.0 and 25 degrees C.
 11. The aqueouscomposition of claim 8, wherein the composition is an emulsioncomprising an effective amount of the pH responsive polymer, and furthercomprises an emulsifier and a film forming polymer latex.
 12. Theaqueous composition of claim 11, wherein the emulsion is selected fromthe group consisting of a latex paint, a latex coating, a cosmetic, adetergent/cleanser, and an oilfield drilling fluid, and wherein the pHresponsive polymer is present in an amount effective for modifying therheological properties of the emulsion.
 13. The aqueous composition ofclaim 11, wherein the emulsion is a latex paint and further comprisingat least one additive selected from the group consisting of dispersants,surfactants, rheology modifiers, defoamers, thickeners, biocides,mildewcides, colorants, waxes.
 14. The aqueous composition of claim 8,wherein the composition is a personal care composition and furthercomprises one or more surfactants.
 15. The aqueous composition of claim14, wherein the one or more surfactants comprise at least one anionicsurfactant and the composition further comprises a structuring agent forthe anionic surfactant.
 16. The aqueous composition of claim 14, furthercomprising a personal care benefit agent.
 17. The aqueous composition ofclaim 8, wherein the composition is a particle dispersion and furthercomprises particles dispersed in the composition.
 18. The aqueouscomposition of claim 8, wherein the composition is a hydraulicfracturing composition and further comprises a proppant.
 19. A methodfor inhibiting settling of particles in an aqueous composition, themethod comprising adding the polymer of claim 1 to an aqueouscomposition.
 20. A method for inhibiting settling of particles in anaqueous composition, the method comprising forming the aqueouscomposition by combining the polymer of claim 1, water and theparticles.
 21. The method of claim 20, wherein the aqueous compositionis a coating composition having a viscosity of less than about 200 KU.22. The method of claim 20, wherein the aqueous composition is a coatingcomposition having a viscosity of less than about 100 KU and wherein thepolymer has a weight average molecular weight of less than about 250,000g/mol.
 23. The method of claim 20, wherein the aqueous composition is anaqueous paint composition comprising a resin binder, particles selectedfrom the group consisting of pigments, fillers and reflecting agents,and water or a water-miscible solvent.
 24. A method comprising directinga stream of the composition of claim 18 into a subterranean formation.25. A method for fracturing a geologic formation, comprising directing astream of the composition of claim 18 at a surface of the formation at apressure and flow rate at least sufficient to initiate, extend, orinitiate and extend one or more fractures in the formation.
 26. A methodfor thickening an aqueous emulsion comprising forming a blend byblending the aqueous emulsion with the polymer of claim 1 in an amounteffective to thicken the aqueous emulsion when pH of the blend isadjusted to a pH in the range of about 6.5 to about 11, wherein thepolymer is a pH responsive polymer.
 27. A method for promoting personalcare comprising applying the polymer of claim 1 to skin or hair of auser.
 28. A home care or industrial cleaning composition for cleaningfabrics or hard surfaces comprising the polymer of claim 1, asurfactant, and one of a home care agent or an industrial benefit agent.29. A method for cleaning a substrate selected from the group consistingof a hard surface and a fabric, comprising applying the polymer of claim1 to the substrate.
 30. The polymer of claim 1, wherein the at least onecarboxylic acid monomer comprises methacrylic acid, and the at least onecopolymerizable non-ionic C₂-C₁₂ alpha beta-ethylenically unsaturatedmonomer comprises ethyl acrylate.